10ASTM A749A749M 热轧高强度碳素低合金钢带材的标准规范
Designation:A749/A749M–97(Reapproved2002)
Standard Speci?cation for
Steel,Strip,Carbon and High-Strength,Low-Alloy,Hot-Rolled,General Requirements for1
This standard is issued under the?xed designation A749/A749M;the number immediately following the designation indicates the year of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.
A superscript epsilon(e)indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1.Scope
1.1This speci?cation covers the general requirements for hot-rolled steel strip in coils and cut lengths.It applies to carbon steel and high-strength,low-alloy steel furnished as hot-rolled.
1.2This speci?cation is not applicable to hot-rolled heavy-thickness carbon sheet and strip coils(ASTM Speci?cation A635/A635M),cold-rolled carbon steel strip(ASTM Speci-?cation A109or A109M),high-strength,low-alloy cold-rolled steel(ASTM Speci?cations A606and A607)or cold-rolled carbon spring steel(ASTM Speci?cation A682or A682M).
1.3In case of any con?ict in requirements,the requirements of the individual material speci?cation shall prevail over those of this general speci?cation.
1.4For the purposes of determining conformance with this and the appropriate product speci?cation referenced under
2.1, values shall be rounded to the nearest unit in the right hand place of?gures used in expressing the limiting values in accordance with the rounding method of Practice E29.
1.5Annex A1lists permissible variations in dimensions and mass(Note1)in SI[metric]units.The values listed are not exact conversions of the values listed in the inch-pound tables, but instead are rounded or rationalized values.Conformance to Annex A1is mandatory when the“M”speci?cation is used. N OTE1—The term“weight”is used when inch-pound units are the standard;however,under SI,the preferred term is“mass.”
1.6The values stated in either inch-pound units or SI units are to be regarded as standard.Within the text,the SI units are shown in brackets.The values stated in each system are not exact equivalents;therefore,each system must be used inde-pendently of the https://www.wendangku.net/doc/6817237699.html,bining values from the two systems may result in nonconformance with the speci?cation.
1.7This speci?cation and the applicable material speci?ca-tions are expressed in both inch-pound units and SI units.However,unless the order speci?es the applicable“M”speci-?cation designation(SI units),the material shall be furnished to inch-pound units.
2.Referenced Documents
2.1ASTM Standards:
A109Speci?cation for Steel,Strip,Carbon,Cold-Rolled2 A109M Speci?cation for Steel,Strip,Carbon,Cold-Rolled (Metric)2
A370Test Methods and De?nitions for Mechanical Testing of Steel Products2
A606Speci?cation for Steel,Sheet and Strip,High-Strength,Low-Alloy,Hot-Rolled and Cold-Rolled,with Improved Atmospheric Corrosion Resistance2
A607Speci?cation for Steel,Sheet and Strip,High-Strength,Low-Alloy,Columbium or Vanadium,or Both, Hot-Rolled and Cold-Rolled2
A635/A635M Speci?cation for Steel,Sheet and Strip, Heavy-Thickness Coils,Carbon,Hot-Rolled2
A682Speci?cation for Steel,Strip,High-Carbon,Cold-Rolled,Spring Quality,General Requirements For2
A682M Speci?cation for Steel,Strip,High-Carbon,Cold-Rolled,Spring Quality,General Requirements For(Met-ric)2
A700Practices for Packaging,Marking,and Loading Methods for Steel Products for Domestic Shipment3
A751Test Methods,Practices,and Terminology for Chemical Analysis of Steel Products2
E11Speci?cation for Wire-Cloth Sieves for Testing Pur-poses4
E29Practice for Using Signi?cant Digits in Test Data to Determine Conformance with Speci?cations4
E290Test Method for Semi-Guided Bend Test for Ductility of Metallic Materials5
2.2Military Standards:6
1This speci?cation is under the jurisdiction of ASTM Committee A01on Steel, Stainless Steel,and Related Alloys,and is the direct responsibility of Subcommittee A01.19on Steel Sheet and Strip.
Current edition approved November10,2002.Published January2003.Origi-nally approved https://www.wendangku.net/doc/6817237699.html,st previous edition approved in1997as A749–97.
2Annual Book of ASTM Standards,V ol01.03.
3Annual Book of ASTM Standards,V ol01.05.
4Annual Book of ASTM Standards,V ol14.02.
5Annual Book of ASTM Standards,V ol03.01.
6Available from Standardization Documents Order Desk,Bldg.4Section D,700 Robbins Ave.,Philadelphia,PA19111-5094,Attn:NPODS.
1
Copyright?ASTM International,100Barr Harbor Drive,PO Box C700,West Conshohocken,PA19428-2959,United States.
MIL-STD-129Marking for Shipment and Storage
MIL-STD-163Steel Mill Products,Preparation for Ship-ment and Storage
2.3Federal Standards:6
Fed.Std.No.123Marking for Shipments(Civil Agencies) Fed.Std.No.183Continuous Identi?cation Marking of Iron and Steel Products
3.Terminology
3.1De?nitions of Terms Speci?c to This Standard:Descrip-tions of Terms Speci?c to This Standard:
3.1.1Steel Types:
3.1.2carbon steel—the designation for steel when no mini-mum content is speci?ed or required for aluminum,chromium, cobalt,columbium,molybdenum,nickel,titanium,tungsten, vanadium,zirconium,or any element added to obtain a desired alloying effect;when the speci?ed minimum for copper does not exceed0.40%;or when the maximum content speci?ed for any of the following elements does not exceed the percentages noted;manganese1.65,silicon0.60,or copper0.60. Discussion—In all carbon steels small quantities of certain residual elements unavoidably retained from raw materials are sometimes found which are not speci?ed or required,such as copper,nickel,molybdenum,chromium,etc.These elements are considered as incidental and are not normally determined or reported.
3.1.3high-strength,low-alloy steel—a speci?c group of steels in which higher strength,and in some cases additional resistance to atmospheric corrosion,are obtained by moderate amounts of one or more alloying elements.
3.1.4Product Types:
3.1.5hot-rolled strip—manufactured by hot rolling billets or slabs to the required thickness.It may be produced single width or by rolling multiple width and slitting to the desired width.It can be supplied in coils or cut lengths as speci?ed.
Width,in.Thickness,in.
Over Through Over Through
...31?20.0440.203
31?260.0440.203
6120.0440.230excl Width,mm Thickness,mm
Over Through Over Through
...100 1.2 5.0
100200 1.2 5.0
200300 1.2 6.0,excl
Hot-rolled,high-strength,low-alloy strip is commonly avail-able by size as follows:
Width,in.Thickness,in.
Over Through From Through
Coils&Cut Lengths Coils Only
(6)
6
12
0.054
0.054
0.203
0.230
0.230excl
0.230excl Width,mm Thickness,mm
Over Through Over Through
(200200)
300
1.8
1.8
5.0
6.0,excl
4.Materials and Manufacture
4.1Unless otherwise speci?ed,hot-rolled material shall be
furnished hot-rolled,not annealed or pickled.
5.Chemical Composition
5.1Limits:
5.1.1The chemical composition shall be in accordance with
the applicable product speci?cation.However,if other compo-
sitions are required for carbon steel,they shall be prepared in
accordance with Appendix X1.
5.1.2Where the material is used for fabrication by welding,
care must be exercised in the selection of chemical composi-
tion or mechanical properties to ensure compatibility with the
welding process and its effect on altering the properties.
5.2Cast or Heat(Formerly Ladle)Analysis:
5.2.1An analysis of each cast or heat of steel shall be made
by the manufacturer to determine the percentage of elements
speci?ed or restricted by the applicable speci?cation.
5.2.2When requested,cast or heat analysis for elements
listed or required shall be reported to the purchaser or to his
representative.
5.3Product,Check,or Veri?cation Analysis:
5.3.1Nonkilled steels(such as capped or rimmed)are not
technologically suited to product analysis due to the nonuni-
form character of their chemical composition and therefore,the
tolerances in Table1do not apply.Product analysis is appro-
priate on these types of steel only when misapplication is
apparent or for copper when copper steel is speci?ed.
5.3.2For steels other than nonkilled(capped or rimmed),
product analysis may be made by the purchaser.The chemical
analysis shall not vary from the limits speci?ed by more than
the amounts in Table1.The several determinations of any
element in a cast shall not vary both above and below the
speci?ed range.
5.4Sampling for Product Analysis:
5.4.1To indicate adequately the representative composition
of a cast by product analysis,it is general practice to select
samples to represent the steel,as fairly as possible,from a
minimum number of pieces as follows:3pieces for lots up to
15tons inclusive,and6pieces for lots over15tons[15Mg].
5.4.2When the steel is subject to tension test requirements,
samples for product analysis may be taken either by drilling
TABLE1Tolerances for Product Analysis A
Element Limit,or Maximum of
Speci?ed
Element,%
Tolerances
Under Minimum
Limit
Over Maximum
Limit
Carbon to0.15,incl0.020.03
over0.15to0.40,incl0.030.04
over0.40to0.80,incl0.030.05
over0.800.030.06
Manganese to0.60,incl0.030.03
over0.60to1.15,incl0.040.04
over1.15to1.65,incl0.050.05
Phosphorus...0.01
Sulfur...0.01
Silicon to0.30,incl0.02
0.03
over0.30to0.60,incl0.050.05
Copper0.02...
A See6.3.1.
entirely through the used tension test specimens themselves or in accordance with5.4.3.
5.4.3When the steel is not subject to tension test require-ments,the samples for analysis must be taken by milling or drilling entirely through the strip in a sufficient number of places so that the samples are representative of the entire strip. The sampling may be facilitated by folding the strip both ways, so that several samples may be taken at one drilling.Steel subjected to certain heating operations by the purchaser may not give chemical analysis results that properly represent its original composition.Therefore,users must analyze chips taken from the steel in the condition in which it is received from the steel manufacturer.
5.5Specimen Preparation—Drillings or chips must be taken without the application of water,oil,or other lubricant, and must be free of scale,grease,dirt,or other foreign substances.They must not be overheated during cutting to the extent of causing decarburization.Chips must be well mixed, and those too coarse to pass a No.10(2.00-mm)sieve or too ?ne to remain on a No.30(600-μm)sieve are not suitable for proper analysis.Sieve size numbers are in accordance with Speci?cation E11.
5.6Test Methods—In case a referee analysis is required and agreed upon to resolve a dispute concerning the results of a chemical analysis,the procedure for performing the referee analysis must be in accordance with the latest issue of Test Methods,Practices,and Terminology A751,unless otherwise agreed upon between the manufacturer and the purchaser.
6.Mechanical Properties
6.1The mechanical property requirements,number of specimens,test locations,and specimen orientation shall be in accordance with the applicable product speci?cation.
6.2Unless otherwise speci?ed in the applicable product speci?cation,test specimens must be prepared in accordance with Test Methods and De?nitions A370.
6.3Mechanical tests shall be conducted in accordance with Test Methods and De?nitions A370.
6.4Bend tests,where required,shall be conducted in compliance with Test Methods E290.
6.5To determine conformance with the product speci?ca-tion,a calculated value should be rounded to the nearest1ksi [7MPa]tensile strength and yield point or yield strength,and to the nearest unit in the right hand place of?gures used in expressing the limiting value for other values in accordance with the rounding off method given in Practice E29.
6.6Structural steels are commonly fabricated by cold bend-ing.There are many interrelated factors that affect the ability of a given steel to cold form over a given radius under shop conditions.These factors include thickness,strength level, degree of restraint,relationship to rolling direction,chemistry, and microstructure.Each of the appropriate product speci?ca-tions lists in the appendix the suggested minimum inside radius for cold bending.These radii should be used as minima for90°bends.They presuppose“hard way”bending(bend axis parallel to rolling direction)and reasonably good shop forming practices.Where possible,the use of larger radii or“easy way”bends are recommended for improved performance.
7.7Fabricators should be aware that cracks may initiate upon bending a sheared or burned edge.This is not considered to be a fault of the steel but is rather a function of the induced cold-work or heat-affected zone.
7.Dimensions,Tolerances,and Allowances
7.1Dimensions,tolerances,and allowances applicable to products covered by this speci?cation are contained in Tables 2-9[Annex A1,Tables A1.1-A1.7].The appropriate tolerance tables shall be identi?ed in each individual speci?cation.
8.Workmanship
8.1Cut lengths shall have a workmanlike appearance and shall not have imperfections of a nature or degree for the product,the grade,and the quality ordered that will be detrimental to the fabrication of the?nished part.
8.2Coils may contain some abnormal imperfections that render a portion of the coil unusable since the inspection of coils does not afford the producer the same opportunity to remove portions containing imperfections as in the case with cut lengths.
9.Finish and Condition
9.1Hot-rolled strip has a surface with an oxide or scale resulting from the hot-rolling operation.The oxide or scale can be removed by pickling or blast cleaning when required for press-work operations or welding.Hot-rolled and hot-rolled descaled strip are not generally used for exposed parts where surface is of prime importance.However,hot-rolled surface might be of importance,as in the case of weathering steels for exposed parts.
9.1.1Hot-rolled strip can be supplied with mill edges, square edges,or cut(slit)edges as speci?ed.
9.1.1.1Mill edges are the natural edges resulting from the hot-rolling operation and are generally round and smooth without any de?nite contour.
9.1.1.2Square edges are the edges resulting from rolling through vertical edging rolls during the hot-rolling operations. These edges are square and smooth,with the corners slightly rounded.
9.1.1.3Cut(slit)edges are the normal edges that result from the shearing,slitting,or trimming of mill edges.
9.1.2The ends of plain hot-rolled mill-edge coils are irregular in shape and are referred to as uncropped ends.Where such ends are not acceptable,the purchaser’s order should so specify.Processed coils such as pickled or blast cleaned are supplied with square-cut ends.
9.2Oiling:
TABLE2Index of Tables for Dimensions,Tolerances,and
Allowances
Dimensions Table No.
Inch-Pound Units
SI Units
Camber tolerances8A1.6
Crown tolerances5A1.3
Flatness tolerances9A1.7
Length tolerances7A1.5 Thickness tolerances3,
4A1.1,A1.2 Width tolerances6A1.4
9.2.1Plain hot-rolled strip is customarily furnished not
oiled.Oiling must be speci?ed when required
9.2.2Hot-rolled pickled or descaled strip is customarily furnished oiled.If the product is not to be oiled,it must be so speci?ed since the cleaned surface is prone to rusting.
10.General Requirements for Delivery
10.1Products covered by this speci?cation are produced to inch-pound or metric decimal thickness only.
10.2Steel may be produced as ingot-cast or strand-cast. When different grades of strand-cast steel are sequentially cast, identi?cation and separation of the transition material is required.
11.Retests
11.1If any test specimen shows defective machining or develops?aws,it must be discarded and another specimen substituted.
11.2If the percentage of elongation of any tension test specimen is less than that speci?ed and any part of the fracture is more than3?4in.[20mm]from the center of the gage length of a2-in.[50mm]specimen or is outside the middle half of the gage length of an8-in.[200mm]specimen,as indicated by scribe scratches marked on the specimen before testing,a retest is allowed.
11.3If a bend specimen fails,due to conditions of bending more severe than required by the speci?cation,a retest is permitted either on a duplicate specimen or on a remaining portion of the failed specimen.
12.Inspection
12.1When the purchaser’s order stipulates that inspection and test(except product analyses)for acceptance on the steel be made prior to shipment from the mill,the manufacturer shall afford the purchaser’s inspector all reasonable facilities to
TABLE3Thickness Tolerances of Hot-Rolled Strip A(Carbon and High-Strength,Low-Alloy Steel)
Ordered to Nominal Thickness
(Coils and Cut Lengths,Including Pickled)
N OTE1—Micrometres used for measurement of thickness shall be constructed with either?at anvils having a minimum diameter of0.188in.or rounded anvils having a minimum radius of curvature of0.100in.Micrometres with pointed anvils are not suitable for thickness measurement.
Speci?ed Width,in.Thickness Tolerance,Over and Under,in.,for Speci?ed Nominal Thickness,in.
Over Through Through0.057Over0.057to
0.118,incl
Over0.118to
0.187,incl
Over0.187to
0.203,incl
Over0.203to
0.230,excl
...3?0.0030.0040.0050.006...
3?60.0030.0050.0050.006...
6120.0040.0050.0050.0060.006
A Measurements for the above table are taken"in.from the edge of a strip on1in.or wider;and at any place on the strip when narrower than1in.The given tolerances do not include crown and therefore the tolerances for crown as shown in Table5are in addition to tolerances in Table3.
TABLE4Thickness Tolerances of Hot-Rolled Strip A(Carbon and High-Strength,Low-Alloy Steel)Ordered to Minimum Thickness
(Coils and Cut Lengths,Including Pickling)
N OTE1—Micrometres used for measurement of thickness shall be constructed with either?at anvils having a minimum diameter of0.188in.or rounded anvils having a minimum radius of curvature of0.100in.Micrometres with pointed anvils are not suitable for thickness measurement.
Speci?ed Width,in.Thickness Tolerance,Over Only,for Speci?ed Minimum Thickness,in.
Over Through Through0.057Over0.057to
0.118,incl
Over0.118to
0.187,incl
Over0.187to
0.203,incl
Over0.203to
0.230,excl
...31?20.0060.0080.0100.012...
31?260.0060.0100.0100.012...
6120.0080.0100.0100.0120.012
A Measurements for the above table are taken"in.from the edge of a strip on1in.or wider;and at any place on the strip when narrower than1in.The given tolerances do not include crown and therefore the tolerances for crown as shown in Table5are in addition to tolerances in Table4Table4.
TABLE5Crown Tolerances of Hot-Rolled Strip(Carbon and
High-Strength,Low-Alloy Steel)
(Coils and Cut Lengths,Including Pickled)
Strip may be thicker at the center than at a point3?8in.from the
edge by the following amounts:
Speci?ed Width,in.Crown Tolerance,Over Only,for Speci?ed
Minimum Thickness,in.
Over Through Through
0.118
Over0.118
to0.187,
incl
Over0.187
to0.230,
excl
...31?20.0020.0020.001 31?260.0030.0020.002 6120.0040.0030.003
TABLE6Width Tolerances of Hot-Rolled Strip(Carbon and
High-Strength,Low-Alloy Steel)
(Coils and Cut Lengths,Including Pickled) Speci?ed Width,
in.
Width Tolerance,Over and
Under,in.
Over Through
Mill Edge
and Square
Edge Strip
Cut Edge
Through
0.109
in.
Over 0.109in. Through 0.230excl
...21?320.0080.016 253?640.0080.016 5101?160.0100.016 10123?320.0160.016
satisfy him that the steel is being produced and furnished in accordance with the speci?https://www.wendangku.net/doc/6817237699.html,l inspection by the purchaser shall not interfere unnecessarily with the manufac-turer’s operation.
13.Rejection and Rehearing
13.1Unless otherwise speci?ed,any rejection shall be reported to the manufacturer within a reasonable time after receipt of material by the purchaser.
13.2Material that is reported to be defective subsequent to the acceptance at the purchaser’s works shall be set aside,adequately protected,and correctly identi?ed.The manufac-turer shall be noti?ed as soon as possible so that an investiga-tion may be initiated.
13.3Samples that are representative of the rejected material shall be made available to the manufacturer.In the event that the manufacturer is dissatis?ed with the rejection,he may request a rehearing.
14.Test Reports and Certi?cation
14.1When test reports are required by the purchase order or the material speci?cation,the supplier shall report the results of all tests required by the material speci?cation and the order.
14.2When certi?cation is required by the purchase order,the supplier shall furnish a certi?cation that the material has been manufactured and tested in accordance with the require-ments of the material speci?cation.
14.3A signature is not required on test reports or certi?ca-tions.However,the document shall clearly identify the orga-nization submitting the document.Notwithstanding the ab-sence of a signature,the organization submitting the document is responsible for the content of the document.
14.4When test reports are required,copies of the original material manufacturer’s test report shall be included with any subsequent test report.
14.5A material test report,certi?cate of inspection,or similar document printed from or used in electronic form from an electronic data interchange (EDI)transmission shall be regarded as having the same validity as a counterpart printed in the certi?er’s facility.The content of the EDI transmitted document must meet the requirements of the invoked ASTM standard(s)and conform to any existing EDI agreement be-tween the purchaser and the supplier.Notwithstanding the absence of a signature,the organization submitting the EDI transmission is responsible for the content of the report.
N OTE 2—The industry de?nition as invoked here is:EDI is the computer to computer exchange of business information in an agreed upon standard format such as ANSI ASC X12.
15.Marking
15.1As a minimum requirement,the material shall be identi?ed by having the manufacturer’s name,ASTM designa-tion,weight,purchaser’s order number,and material identi?-cation legibly stenciled on top of each lift or shown on a tag attached to each coil or shipping unit.
15.2When speci?ed in the contract or order,and for direct procurement by or direct shipment to the government,marking for shipment,in addition to requirements speci?ed in the contract or order,shall be in accordance with MIL-STD-129for military agencies and in accordance with Fed.Std.No.123for civil agencies.
15.3For Government procurement by the Defense Supply Agency,strip material shall be continuously marked for iden-ti?cation in accordance with Fed.Std.No.183.
15.4Bar coding is acceptable as a supplementary identi?-cation method.Bar coding should be consistent with the Automotive Industry Action Group (AIAG)standard prepared by the primary metals subcommittee of the AIAG bar code project team.
TABLE 7Length Tolerances of Hot-Rolled Strip (Carbon and High-Strength Alloy)
(Cut Lengths,Including Pickled)
Speci?ed Widths,in.Length Tolerances over Speci?ed Length,ft for Widths Given,in.No Tolerance Under
To 5ft,incl
Over 5to 10ft,
incl
Over 10to 20ft,
incl
Over 20to 30ft,
incl
Over 30to 40ft,
incl
Over 40ft,
incl
To 3,incl
1?4"1?23?4111?2Over 3to 6,incl 3?8
1?2
5?8
3?4
111?2Over 6to 12,incl
1?2
3?4
1
11?4
11?2
13?4
TABLE 8Camber Tolerances A of Hot-Rolled Strip
(Carbon and High-Strength Low-Alloy)
(Coils and Cut Lengths,Including Pickled,Applicable to Mill
Edge,Square Edge,and Slit or Cut Edge)
N OTE 1—Camber is the deviation of a side edge from a straight line.The standard for measuring this deviation is based on any 8-ft length.B It is obtained by placing an 8-ft straightedge on the concave side and measuring the maximum distance between the strip edge and the straight-edge.
For strip wider than 11?2in.—1?4in.in any 8ft.For strip 11?2in.and narrower—1?2in.in any 8ft.
A
When the camber tolerances shown in the above table are not suitable for a particular purpose,hot-rolled strip is sometimes machine straightened.B
For strip less than 8ft tolerances are to be established in each instance.A formula for calculating camber is as follows:
L 23C 1
64
5C 2in L where:
C 1=Camber in 8ft and
C 2=Camber in any given length L .
TABLE
9Flatness Tolerances of Hot-Rolled Strip
(Carbon and High-Strength Low-Alloy)
It has not been practicable to formulate ?atness tolerances for hot-rolled carbon strip steel because of the wide range of widths and thicknesses,and variety of chemical compositions,mechanical properties and types,produced in coils and cut lengths.
16.Packaging
16.1Unless otherwise speci?ed,the strip shall be packaged and loaded in accordance with Practices A 700.
16.2When speci?ed in the contract or order,and for direct procurement by or direct shipment to the government,when Level A is speci?ed,preservation,packaging,and packing shall be in accordance with the Level A requirements of MIL-STD-163.
16.3When coils are ordered it is customary to specify a minimum or range of inside diameter,maximum outside diameter,and a maximum coil weight,if required.The ability of manufacturers to meet the maximum coil weights depends upon individual mill equipment.When required,minimum coil weights are subject to negotiation.17.Keywords
17.1carbon;steel;strip
ANNEX
(Mandatory Information)
A1.PERMISSIBLE V ARIATIONS IN DIMENSIONS AND MASS IN SI UNITS
A1.1Listed in Tables A1.1-A1.7are permissible varia-tions in dimensions and mass expressed in the International
System of Units (SI)terminology.
TABLE A1.1Thickness Tolerances of Hot-Rolled Strip A (Carbon and High-Strength,Low-Alloy Steel)Ordered to Nominal Thickness
(Coils and Cut Lengths,Including Pickled)
N OTE 1—Micrometres used for measurement of thickness shall be constructed with either ?at anvils having a minimum diameter of 4.80mm or rounded anvils having a minimum radius of curvature of 2.55mm.Micrometres with pointed anvils are not suitable for thickness measurement.
Speci?ed Width,mm Thickness Tolerance,Over and Under,mm,for Speci?ed Nominal Thickness,mm
Over Through Through 1.5
Over 1.5to 3.0,
incl
Over 3.0to 4.5,
incl
Over 4.5to 5.0,
incl
Over 5.0to 6.0,
excl
...1000.080.100.130.15...1002000.080.130.130.15 (200)
300
0.10
0.13
0.13
0.15
0.15
A
Measurements for the above table are taken 10mm from the edge of a strip on 25mm or
wider;and at any place on the strip when narrower than 25mm.The given tolerances do not include crown and therefore the tolerances for crown as shown in Table A1.3are in addition to tolerances in Table A1.1.
TABLE A1.2Thickness Tolerances of Hot-Rolled Strip A(Carbon and High-Strength,Low-Alloy Steel)Ordered
to Minimum Thickness
(Coils and Cut Lengths,Including Pickling)
N OTE1—Micrometres used for measurement of thickness shall be constructed with either?at anvils having a minimum diameter of4.80mm or rounded anvils having a minimum radius of curvature of2.55mm.Micrometres with pointed anvils are not suitable for thickness measurement.
Speci?ed Width,mm Thickness Tolerance,Over Only,for Speci?ed Minimum Thickness,mm
Over Through Through1.5Over1.5to3.0,
incl
Over3.0to4.5,
incl
Over4.5to5.0,
incl
Over5.0to6.0,
excl
...1000.150.200.250.30...
1002000.150.250.250.30...
2003000.200.250.250.300.30
A Measurements for the above table are taken10mm from the edge of a strip on25mm or wider;and at any place on the strip when narrower than25mm.The given tolerances do not include crown and therefore the tolerances for crown as shown in Table A1.3are in addition to tolerances in Table A1.2.
TABLE A1.3Crown Tolerances of Hot-Rolled Strip(Carbon and
High-Strength,Low-Alloy Steel)
(Coils and Cut Lengths,Including Pickled)
Speci?ed Width,mm Crown Tolerance,Over Only,for Speci?ed Minimum Thickness,mm
Over Through Through
3.0
Over3.0
to4.5,
incl
Over4.5
to6.0,
incl
Over6.0
to9.5,
incl
...1000.050.050.03...
1002000.100.080.05...
2003000.100.080.080.05 TABLE A1.4Width Tolerances of Hot-Rolled Strip(Carbon and
High-Strength,Low-Alloy Steel)
(Coils and Cut Lengths,Including Pickled)
Speci?ed Width,mm Width Tolerance,Over and Under,mm
Over Through
Mill Edge and
Square Edge Strip
Cut Edge
Through2.5mm Over2.5mm
...500.80.20.4
50100 1.20.20.4
100200 1.60.30.4
200300 2.40.40.4
TABLE A1.5Length Tolerances of Hot-Rolled Strip(Carbon and High-Strength,Low-Alloy Steel)
(Cut Lengths,Including Pickled)
Speci?ed Widths,mm Length Tolerances Over Speci?ed Length,for Widths Given,No Tolerance Under,mm
Over Through Through
1500
Over1500to
3000,incl
Over3000to
6000,incl
Over6000to
9000,incl
Over9000to
12000,incl
Over12000
(100101015202540)
100200101515202540 200300152025304045
APPENDIX
(Nonmandatory Information)
X1.STANDARD CHEMICAL RANGES AND LIMITS
X1.1Standard chemical ranges and limits are prescribed for carbon steels in Table X1.1
TABLE X1.1Standard Chemical Ranges and Limits
N OTE 1—The carbon ranges shown in the column headed “Range”apply when the speci?ed maximum limit for manganese does not exceed 1.00%.When the maximum manganese limit exceeds 1.00%,add 0.01to the carbon ranges shown below.
Element
Carbon Steels Only,Cast or Heat Analysis
Minimum of Speci?ed Element,%
Range Lowest,max
Carbon (see Note)
to 0.15,incl
0.050.08
over 0.15to 0.30,incl 0.06over 0.30to 0.40,incl 0.07over 0.40to 0.60,incl 0.08over 0.60to 0.80,incl 0.11over 0.80to 1.35,incl
0.14Manganese to 0.50,incl
0.200.40
over 0.50to 1.15,incl 0.30over 1.15to 1.65,incl
0.35Phosphorus to 0.08,incl
0.030.030A over 0.08to 0.15,incl
0.05Sulfur
to 0.08,incl
0.030.035A
over 0.08to 0.15,incl 0.05over 0.15to 0.23,incl 0.07over 0.23to 0.33,incl
0.10Silicon to 0.15,incl
0.080.10
over 0.15to 0.30,incl 0.15over 0.30to 0.60,incl
0.30
Copper
When copper is required 0.20min is commonly speci?ed.
A
Certain individual speci?cations provide for lower standard limits for phosphorus and sulfur.
TABLE A1.6Camber Tolerances A of Hot-Rolled Strip (Carbon
and High-Strength Low-Alloy)
(Coils and Cut Lengths,Including Pickled,Applicable to Mill
Edge,Square Edge,and Slit or Cut Edge)
N OTE 1—Camber is the deviation of a side edge from a straight line.The standard for measuring this deviation is based on any 2000-mm length.B It is obtained by placing a 2000-mm straightedge on the concave side and measuring the maximum distance between the strip edge and the straightedge.
For strip wider than 50mm—5.0mm in any 2000mm For strip 50mm and narrower—10.0mm in any 2000mm
A
When the camber tolerances shown in the above table are not suitable for a particular purpose,hot-rolled strip is sometimes machine straightened.B
For strip less than 2000mm tolerances are to be established in each instance.
TABLE A1.7Flatness Tolerances of Hot-Rolled Strip (Carbon
and High-Strength Low-Alloy)
It has not been practicable to formulate ?atness tolerances for hot-rolled strip because of the wide range of
widths and thicknesses,and variety of chemical compositions and qualities,produced in coils and cut lengths.
ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned in this https://www.wendangku.net/doc/6817237699.html,ers of this standard are expressly advised that determination of the validity of any such patent rights,and the risk of infringement of such rights,are entirely their own responsibility.
This standard is subject to revision at any time by the responsible technical committee and must be reviewed every?ve years and if not revised,either reapproved or withdrawn.Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM International Headquarters.Your comments will receive careful consideration at a meeting of the responsible technical committee,which you may attend.If you feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards,at the address shown below.
This standard is copyrighted by ASTM International,100Barr Harbor Drive,PO Box C700,West Conshohocken,PA19428-2959, United States.Individual reprints(single or multiple copies)of this standard may be obtained by contacting ASTM at the above address or at610-832-9585(phone),610-832-9555(fax),or service@https://www.wendangku.net/doc/6817237699.html,(e-mail);or through the ASTM website (https://www.wendangku.net/doc/6817237699.html,).
第三节 焊丝
第三节焊丝 一、 焊丝国内外发展概况及分类 1． 焊丝的发展概况 焊丝是埋弧焊、气体保护焊、电渣焊、气焊等焊接工艺中的主要焊接材料，其作用是填充金属，并作为熔化电极传导电流，本章主要介绍气保焊、埋弧焊常用的各类焊丝。 自从1904年瑞典人奥斯卡凯·吉尔伯格建立了世界第一个涂料焊条厂即现在的ESAB公司以来，随着对焊接冶金研究的深入，一方面利用气保护的原理发明了CO2气保焊；另一方面利用渣保护的原理发明了埋弧焊。实心焊丝气保焊从20世纪50年代发展起来，到20世纪70年代又发展了气保护药芯焊丝。 随着焊接自动化水平的提高，促进了自动化焊接材料的发展。根据焊丝与焊材比计算，德国焊接自动化水平达到80%，日本为70%，美国为56%，俄罗斯为40%，我国约为15%。因此我国目前和今后将大力发展和推广使用各类焊丝。在“七五”、“八五”期间，我国重点推广CO2半自动焊接技术，带动了实心焊丝的发展，收到一定成效。目前国内已有近百家实心焊丝生产厂，几十家药芯焊丝生产厂，通过引进吸收消化，我国现已能自行设计制造实心焊丝和药芯焊丝生产线。因此从焊接材料行业来讲，已具备在我国大力使用高效、低成本、自动化焊接技术的条件。为适应我国经济发展的需要，尽快提高我国焊接材料的构成比例，大力发展自动或半自动焊接材料。进一步降低实心焊丝成本，改善焊缝成形，减少飞溅。扩大药芯焊丝品种，提高药芯焊丝质量，开发抗气孔性优良的金属芯焊丝。积极跟踪国际无缝镀铜药芯焊丝、不镀铜实心焊丝的研究开发。全面降低焊接材料发尘量。尽快开展环境协调型焊材的理论研究和应用开发。 2． 焊丝的分类
焊丝的分类方法很多，可按熔敷金属力学性能，按所配套的钢种，按所适用的焊接方法，按焊丝的形状结构等来分类。 1）按焊接方法分类：可分为埋弧焊焊丝，CO2焊焊丝，钨极氩弧焊焊丝，熔化极氩弧焊焊丝，电渣焊焊丝以及自保护焊焊丝。 2）按所配套的钢种分：焊丝可分为低碳钢焊丝，低合金钢焊丝，低合金耐热钢焊丝，不锈钢焊丝，低温钢焊丝，镍基合金焊丝，铝及铝合金焊丝，钛及钛合金焊丝等。 3）按焊丝的形状结构分：焊丝可分为实心焊丝和药芯焊丝。其中药芯焊丝可分为熔渣型，金属芯型及自保护型。 目前较常用的是按制造方法和适用的焊接方法进行分类；见图3.1 电渣焊焊丝 埋弧焊焊丝 实心焊丝 气保护焊焊丝 自保护焊焊丝 焊丝 埋弧焊焊丝 熔渣型 气保护焊焊丝 药芯焊丝 自保护焊焊丝 埋弧焊焊丝 金属型 气保护焊焊丝 自保护焊焊丝 图3.1焊丝的分类 二、 焊丝的型号和牌号 1实心焊丝的型号 1）气保护焊用碳钢、低合金钢焊丝： 焊丝型号的表示方法为ERXX-X，字母“ER”表示焊丝，ER后面的两位数字表示熔敷金属的抗拉强度最低值，短划“－”后面的字母或数字表示焊丝化学成分分类代号。如还附加其他化学元素时，直接用元素符号表示，并以短划“－”与前面数字分开。
低合金高强度结构钢GBT
低合金高强度结构钢GB/T 1591-2008 一，范围 本标准规定了低合金高强度结构钢的牌号、尺寸、外形、重量及允许偏差、技术要求、试验方法、检验规则、包装、标志和质量证明书。 二，规范引用文件 GB/T 222 钢的成品化学成分允许偏差 GB/T 223.5 钢铁酸溶硅和全硅含量的测定还原性硅酸盐分 分光光度法 GB/T 223.9 钢铁及合金铝含量的测定铬天青S分光光度法 GB/T 223.12钢铁及合金化学分析方法碳酸钠分离-二笨碳酰 二肼光度法测铬含量 GB/T 223.14钢铁及合金化学分析方法钽试剂萃取光度法测定钒含量 GB/T 223.16钢铁及合金化学分析方法变色酸光度法测钛含量GB/T 223.19钢铁及合金化学分析方法新亚铜灵三氯甲烷萃取光度法测定铜含量 GB/T 223.23钢铁及合金镍含量的测定丁二酮肟分光光度法 GB/T 223.26 钢铁及合金钼含量的测定硫氰酸盐分光光度法GB/T 223.37钢铁及合金化学分析方法蒸馏分离腚酚蓝光度法测定氮含量 GB/T 223.40 钢铁及合金铌含量的测定氯磺酚S分光光度法
GB/T 223.62钢铁及合金化学分析方法乙酸丁酯萃取光度法测定磷含量 GB/T 223.63钢铁及合金化学分析方法高锰酸钾光度法测锰量GB/T 223.67 钢铁及合金硫含量的测定次甲基蓝分光光度法GB/T 223.69 钢铁及合金碳含量的测定管式炉燃烧气体容量法GB/T 223.78钢铁及合金化学分析方法姜黄素直接光度法测定硼含量 GB/T 228 金属材料室温拉伸试验方法(ISO 6892) GB/T 229 金属材料夏比摆锤冲击试验方法验方法(ISO 148) GB/T 232 金属材料弯曲试验方法(ISO 7438) GB/T 247 钢板和钢带包装、标志、质量证明书的一般规定GB/T 2101 型钢验收包装、标志、质量证明书的一般规定GB/T 2975 钢及钢产品力学性能试验取样位置及试样的制备(ISO 377) GB/T 4336 碳素钢和中低合金钢火花源原子发射光谱分析法GB/T 5313 厚度方向性能钢板(ISO 7778) GB/T 17505 钢及钢产品交货一般技术要求(ISO 404) GB/T 20066 钢和铁化学成分测定用试样的取样和制样方法(ISO 14284) GB/T 20125低合金钢多元素的测定(ISO 7778)电感耦合等离子体原子发射光谱法 YB/T 冶金技术标准的数值修约与检测数据的判定原则
特殊性能低合金高强度钢
特殊性能低合金高强度钢
特殊性能低合金高强度钢 摘要：特殊钢属于工程构件用钢，它是具有特殊的化学成分、采用特殊工艺生产、具备特殊的组织和性能、能够满足特殊需要的钢类。是国民经济各部门不可缺少的重要基础材料。 特殊钢的产量、质量和品种反映出一个国家工业化和科学技术发展的水平，是一个国家工业化水平的重要标志之一。随着知识经济和高技术产业的迅猛发展，对特殊钢提出高性能、多样化、低成本、节约能源，并符合环保和可持续发展的要求。本文主要介绍工程结构用特殊钢。 分类 一、耐候钢 定义： 以保证力学性能为主适当提高耐大气腐蚀性能以延长钢结构件使用寿命的一类刚。分为焊接结构用耐候钢和高耐候钢两类。 耐候钢是在钢中加入少量的合金元素，如Cu、Cr、P、Ni等，使其在金属基体表面上形成保护层，以提高钢材的耐候性能。为了改善钢的性能，可以加入一种或多种微量合金元素，但添加量应当要符合国际标准。 应用： 目前对焊接性要求不高的轻型结构件多采用较便宜的P-Cu系耐候钢。对于韧性和焊接性要求较高额结构件则采用Cr-Cu系耐候钢。 高强度钢主要用在车辆、桥梁、房屋、集装箱等结构的制造中，既满足了高腐蚀性又满足了好的成型性能和焊接性能。例如：我国开发研制的08CuPVRE 耐候钢已经批量用于铁路车辆制造和一些近海设施。 工艺要求 从消除夹杂物的有害影响和改善腐蚀性能两个角度入手，确定加入合金元素的量。 过高的稀土量没有什么意义，要选择合适的稀土含量。 双相区淬火可以得到较高的强韧性配合以及良好的成形性和焊接性。 加工变形可以影响耐候钢热处理时的组织变化。 二、表面处理钢材 定义： 钢材表面镀涂耐蚀合金或有机材料，既经济又显著提高其耐蚀能力。 因为刚的腐蚀都是从表面开始，整体合金化加入的合金元素，90%没有发挥作用，反而增加了成本，有时候还降低了性能，所以采用表面处理钢材。 分类 镀锌板 热镀锌板的平均耐蚀寿命为5~10年。 家电行业镀锌板镀层厚、耐蚀性能好、冲压性能高、生产成本低；采用了深冲电镀锌钢板或进口的深冲小锌花热镀锌板和合金化热镀锌板制作。 汽车用镀层板
焊丝牌号型号对比
药芯焊丝的牌号及型号 我国的不锈钢药芯焊丝牌号有新、旧两个类型。旧类型是历史比较早的药芯焊丝厂家习惯使用的， 其编制方法基本与手工焊条牌号相同，只是牌号前的字母不同(如“Y”)用以区别手工焊条;新类型是新发 展起来的药芯焊丝厂家习惯使用的，其编制方法基本与国家标准GB/T17853-1999《不锈钢药芯焊丝》相同，只是牌号前用不同的字母表示不同的厂家。 国家标准GB/T17853-1999中规定了不锈钢药芯焊丝的型号分类、技术要求、试验方法及检验规则等。该标准规定，所适用的不锈钢药芯焊丝熔敷金属中铬含量应大于10.50％，铁的含量应超过其他任何元素。此外，标准还规定焊丝芯部所含非金属组分应不小于焊丝总重的5％。 GB/T17853-1999中规定的不锈钢药芯焊丝型号编制方法如下:第一位是字母“E”或字母“R”，“E”表示焊丝，“R”表示填充焊丝;后面用三位或四位数字表示熔敷金属化学成分分类代号，如有特殊要求的 化学成分，将其元素符号附加在数字后面，或者用“L”表示碳含量较低、“H”表示碳含量较高、“K”表示焊丝应用于低温环境;再后面用“T”表示药芯焊丝，之后用一位数字表示焊接位置，“0”表示焊丝适用于平焊位置或横焊位置焊接，“1”表示焊丝适用于全位置焊接;后接“-”，“-”后面用数字表示保护气 体及焊接电流类型(见表1)。 表1 备型号不锈钢药芯焊丝的保护气体、电流类型及焊接方法 注:FCAW为药芯焊丝电弧焊，GTAW为钨极惰性气体保护焊。 GB/T17853-1999根据熔敷金属化学成分划分的不锈钢药芯焊丝型号见表2。 表3 各型号不锈钢药芯焊丝的熔敷金属力学性能
中国工具钢和硬质合金牌号及其化学成分
第一章中国工具钢和硬质合金牌号及化学成分 第一节碳素工具钢（1）中国GB标准碳素工具钢的钢号与化学成分[GB/T1298-1986]（表6-1-1） 表6-1-1碳素工具钢的钢号与化学成分（质量分数）（%） 钢号C Si Mn P≤S≤ T7 T8 T8Mn T9 T10 T11 T12 T13 0.65-0.74 0.75-0.84 0.80-0.90 0.85-0.94 0.95-1.04 1.05-1.14 1.15-1.24 1.25-1.35 ≤0.35 ≤0.35 ≤0.35 ≤0.35 ≤0.35 ≤0.35 ≤0.35 ≤0.35 ≤0.40 ≤0.40 0.40-0.60 ≤0.40 ≤0.40 ≤0.40 ≤0.40 ≤0.40 0.035 0.035 0.035 0.035 0.035 0.035 0.035 0.035 0.030 0.030 0.030 0.030 0.030 0.030 0.030 0.030 注：1.高级优质钢（带“A”的钢号）磷、硫含量（质量分数）：P≤0.030%；S≤0.030%。 2.钢中残余元素含量（质量分数）：Cr≤0.25%，Ni≤0.20%，Cu≤0.30%。 3.用作铅浴钢丝的残余元素含量（质量分数）：Cr≤0.10%，Ni≤0.12%，Cu≤0.20%，Cr+Ni+Cu≤0.40%。 4.要求检验钢的淬透性时，允许添加少量合金元素。 （2）中国GB标准碳素工具钢的交货硬度与淬火硬度（表6-1-2和表6-1-3） 表6-1-2碳素工具钢的交货硬度与淬火硬度钢号 交货状态试样淬火 硬度HBS压痕直径/mm淬火温度/℃冷却介质硬度＞HRC T7≤187≥4.4800-820水62 T8≤187≥4.4780-800水62 T8Mn≤187≥4.4780-800水62 T9≤192≥4.35760-780水62
焊材的表示方法和代号
焊条、药芯焊丝的表示方法和代号 作为焊缝填充金属包括焊条、焊丝、焊剂、填充金属、熔嘴、附加金属粉等，熔敷焊缝金属成分主要由它们和母材来决定。ASME《锅炉压力容器规范》第IX卷中列有工艺评定中焊缝金属成分的类别，并有相应的评定规则。我国的钢材和焊材的合金化体系与美国差别较大，况且国内压力容器压力管道熟悉焊材牌号程度胜过型号，原机械工业部编制的《焊接材料产品样本》（机械工业出版社，1997年）规定的焊条、焊剂和药芯焊丝的牌号对焊接行业、压力容器压力管道行业影响很大，焊材牌号编制比较切合我国合金体系的实际。我国焊材基本上与钢材使用性能相适应，不同牌号焊材性能差别很大，用焊材牌号作为焊接工艺评定因素具有简便特点，但也有局限性，焊材牌号编制方法不是标准。随着技术与市场经济发展，在焊材牌号前后加上代号或化学成分符号，使牌号复杂化。 将牌号作为焊接工艺评定因素时不考虑阿拉伯数字后的代号（耐蚀层堆焊除外）。(1）我国焊条分类对照附表1所示，焊条和药芯焊丝牌号编制方法如下述： ①碳钢焊条和低合金高强钢焊条牌号表示方法 a）牌号前加“J”字表示为碳钢焊条或低合金高强钢焊接类别代号。 b）类别代号后头两位数字，表示焊缝金属抗拉强度等级，其系列如附表2。 c）类别代号后第三位数字，表示药皮类型和焊接电源类，见附表3。 d）焊条有特殊性能和用途的，则在牌号后面加注起主要作用的元素或代表主要用途的符号，见附表4。 附表1
附表2 附表3
附表4
②铬和铬钼耐热钢焊条牌号表示方法 a）牌号前加“R”字，表示钼和铬钼耐热钢焊条的类别代号 b）类别代号后第一位数字，表示焊缝金属主要化学成分等级，按附表5规定编排表。 c）类别代号后第二位数字，表示同一焊缝金属主要化学成分组成等级中的不同牌号，对同一药皮类型焊条，可有10个牌号，按0、1、2、…9顺序编排。 d）类别代号后第三位数字，表示药皮类型和焊接电源种类，见附表3。 附表5 ③低温钢焊条牌号表示方法 a）牌号前加“W ”字，表示低温钢焊条的类别代号。
合金钢习题(答案)
合金钢 一、填空题 1.合金钢按主要用途可分为合金结构钢、合金工具钢和特殊性能钢三 大类。 2.合金钢按合金元素总量高低可分为低合金钢、中合金钢和高合金钢三种。 3.合金结构钢又细分为普通低合金结构钢、合金渗碳钢、合金调质钢、 合金弹簧钢和滚动轴承钢五类。 4.调质钢的含碳量一般在0.25%至0.5 %之间。 5.合金刃具钢分为低合金刃具钢和高速钢两类。 6.高速钢在600℃以下工作时，硬度仍保持在HRC60以上，具有高的红硬性。 二、判断题（对的打“√”，错的打“×”） 1.合金钢是多种钢混合而成的混合物。（×） 2.合金钢因为含有合金元素，所以比碳钢淬透性差。（×） 3.大部分合金钢淬透性都比碳钢好。（√） 4.除Fe、C外还含有其他元素的钢就是合金钢。（×） 5.低合金钢是指含碳量低于0.25%的合金钢。（×） 6.40Cr是最常用的合金调质钢。（√） 7.合金结构钢都是高级优质钢。（×） 8.合金工具钢都是高级优质钢。（√） 9.钢的淬透性是指钢淬火时能够达到的最高硬度。（×） 10.碳钢淬透性比合金钢好（×） 11.3Cr2W8V的平均含碳量为0.3%，所以它是合金结构钢。（×） 12.GCr15是滚动轴承钢，但又可以制造柴油机中的精密偶件。（√） 13.特殊性能钢简称特类钢。（×） 14.16Mn的含碳量为0.16%，是较高含锰量的优质碳素结构钢。（×） 15.W6Mo5Cr4V2是高速钢。（√） 16.Cr12MoV是不锈钢。（×） 17.1Cr18Ni9Ti是合金工具钢。（×）
18.60Si2Mn是合金弹簧钢。（√） 19.GCr15既可做滚动轴承，也可做量具。（√） 20.含铬的钢都是不锈钢。（×） 三、单项选择题 1.合金钢除有较高的强度、比强度、热硬性和特殊的理化性能外，还有较高的 。 A．淬硬性B．淬透性C．减振性D．变形抗力 2.调质钢大多是 A．高碳钢B．低碳钢C．中碳钢D．B或C 3.合金结构钢主要是 A．低合金结构钢B．合金渗碳钢和合金弹簧钢 C．合金调质钢和滚珠轴承钢D．A+B+C 4.制造船舶、桥梁、大型钢结构的钢材是 A．普通碳素结构钢B．普通低合金结构钢 C．低合金调质钢D．不锈钢 5.制造南京长江大桥的材料是 A．优质碳素结构钢B．高合金钢 C．合金调质钢D．普通低合金钢 6.属于合金调质钢的是材料 A．20Cr B．40Cr C．4Cr9Si2 D．4Cr13 7.调质钢要求含碳量在一定的范围，如含碳量过低，则；含碳量过高， 则。 A．强度低/刚度低B．刚度低/强度低 C．韧性低/疲劳性能低D．硬度低/韧性低 8.下列钢材中属于合金钢的是。 A．20 B．40Cr C．ZG200—400 D．H62 9.生产中对较重要的零件（如汽车、拖拉机齿轮等）及对于截面较大或心部强度要 求较高的渗碳零件，通常采用来制造。 A．含碳量较低（0.10～0.25%）的钢B．含碳量为0.30%的钢
GBt1591-94低合金高强度钢
返回 中华人民共和国国家标 准 低合金高强度结构钢GB/T1591-94 High strength low alloy 代替GB1591-88 structural steels 本标准参照采用IS04950：1981《高屈服强度扁平钢材》和IS04951：1979《高屈服强度钢棒材和型材》。 1 主题内容与适用范围 本标准规定了低合金高强度结构钢的牌号和技术要求、试验方法、检验规则、包装、标志及质量证明书等。 本标准适用于热轧、控轧、正火、正火加回火及淬火加回火状态供应的工程用钢和一般结构用厚度不小于3mm的钢板、钢带及型钢、钢棒,一般在供应状态下使用。 本标准规定低合金高强度结构钢的化学成分也适用于钢锭、连铸坯、钢坯及其制品。 2 引用标准
3 牌号表示方法 钢的牌号由代表屈服点的汉语拼音字母(Q)、屈服点数值、质量等级符号(A、B、C、D、E)三个部分按顺序排列。 例如:Q390A 其中: Q--钢材屈服点的"屈"字汉语拼音的首位字母; 390--屈服点数值,单位MPa ;
A、B、C、D、E一一分别为质量等级符号。 4 尺寸、外形、重量等要求 尺寸、外形、重量及允许偏差应符合相应标准的规定 5 技术要求 5.1 牌号和化学成分 5.1.1 钢的牌号和化学成分(熔炼分析)应符合表1规定。合金元素含量应符合GB/T13304对低合金钢的规定。 注:表中的AI为全铝含量。如化验酸溶铝时,其含量应不小于0.010%。 5.1.1.1 Q295的碳含量39j0.18%也可交货。 5.1.1.2 不加V、Nb、Ti的Q295级钢,当C≤0.12%时,Mn含量上限可提高到1.80%。 5.1.1.3 Q345级钢的Mn含量上限可提高到1.70%。
硬质合金牌号性能对照表
硬质合金牌号性能、应用推荐及牌号对照 合金牌号 密度 g/cm2 抗弯 强度 不低 于 N/cm2 硬度 不低 于 HRA 加工条件及用途 ISO 国际标准 YT15 11.0- 11.7 1150 91 适用于碳素钢与合金钢加工中，连续切削时的粗车、半精车 及精车，间断切削时的小断面精车，连续面的半精铣与精铣， 孔的粗扩与精扩。 P10 YT14 11.2- 12.0 1270 90.5 适于在碳素钢与合金钢加工中，不平整断面和连续切削时的 粗车，间断切削时的半精车与精车，连续断面粗铣，铸孔的 扩钻与粗扩。 P20 YT5 12.5- 13.2 1430 89.5 适于碳素钢与合金钢（包括钢锻件，冲压件及铸件的表皮） 加工不平整断面与间断切削时的粗车、粗刨、半精刨，非连 续面的粗铣及钻孔。 P30 YS25 12.8- 13.2 2000 91 适应于碳素钢、铸钢、高锰钢、高强度钢及合金钢的粗车、 铣削和刨削。 P20、P40 YS30 12.45 1800 91 属超细颗粒合金，适于大走刀高效率铣削各种钢材，尤其是 合金钢的铣削。 P25 P30 YW1 12.6- 13.5 1180 91.5 适于耐热钢、高锰钢、不锈钢等难加工钢材及普通钢和铸铁 的加工。 M10 YW2 12.4- 13.5 1350 90.5 适于耐热钢、高锰钢、不锈钢及高级合金钢等特殊难加工钢 材的精加工，半精加工。普通钢材和铸铁的加工。 M20 YW3 12.7- 13.3 1300 92 适于合金钢、高强度钢、低合金、超强度钢的精加工和半精 加工。亦可在冲击力小的情况下精加工。 M10、M20 YL10.1 14.9 1900 91.5 具有较好的耐磨性和抗弯强度，主要用为生产挤压棒材，适 合做一般钻头、刀具等耐磨件。 K15、K25 M10、M30 YL10.2 14.5 2200 91.5 具有很好的耐磨性和抗弯强度，主要用来生产挤压棒材，制 作小直径微型钻头、钟表加工用刀具，整体铰刀等其它刃具 和耐磨零件。 K25、K35 M25、M40 YG3X 14.6- 15.2 1320 92 适于铸铁、有色金属及合金淬火钢合金钢小切削断面高速精 加工。 K05 YG6A 14.6- 15.0 1370 91.5 适于硬铸铁，有色金属及其合金的半精加工，亦适于高锰钢、 淬火钢、合金钢的半精加工及精加工。 K10
药芯焊丝牌号对照表
药芯焊丝牌号对照表
字体大小：大 | 中 | 小 2009-04-17 16:13 - 阅读：812 - 评论：1
药芯焊丝牌号对照表
序 号
符 合 GB
结构钢用药芯焊丝
相当标准 AWS JIS
Z3313 1 GB/T 10045-2001 E500T-1 A5.20 E70T-1 YFW-C50DR Z3313 2 GB/T 10045-2001 E501T-1 A5.20 E71T-1 YFW-C50DR Z3313 3 GB/T 10045-2001 E500T-5 A5.20 E70T-5 YFW-C503B A5.29 4 -----------E81T1-Ni1 5 GB/T 10045-2001 E500T-1 A5.20 E70T-1 YFW-C603R Z3313 YFW-C50DR Z3313 YFL-C504R Z3320 YFA-50W Z3313
6 -----------7 ------------
----------------A5.29
8 GB/T 17493-1998 E550T1-W E80T1-W 耐热钢用药芯焊丝 9 GB/T 17493-1998 E551T1-A1 A5.29 E81T1-A1 A5.29 E81T1-B1
Z3320 YFA-58W
Z3318 YFM-C
10 GB/T 17493-1998 E551T1-B1
Z3318 YFCM-C Z3318 YF1CM-C
11 GB/T 17493-1998 E551T1-B2 A5.29
(推荐)GBT1591-2018低合金高强度结构钢
目次 前言 (1) 1范围 (1) 2规范性引用文件 (1) 3术语和定义 (2) 4牌号表示方法 (3) 5订货内容 (3) 6尺寸、外形.重量 (3) 7技术要求 (4) 8实验方法 (16) 9检验规则 (16) 10包装、标识和质量证明书 (17) 附录A (资料性附录)国内外标准牌号对照表 (18)
前言 本标准按照GB/T 1.1- 2009 给出的规则起草。 本标准代替GB/T 1591- -2008( 低合金高强度结构钢》。与GB/T 1591- -2008相比除编辑性修改外主要技术变化如下: ——明确了本标准的化学成分也适用于钢坯(见第1章,2008版第1章); ——修改了“热机械轧制”及“正火轧制”术语的定义,增加了“热轧”、“正火”术语与定义(见第3章，2008版第3章); ——修改了牌号表示方法(见第4 章,2008版第4章); ——增加了订货内容(见第5章); ——明确了尺寸外形、重量及允许偏差要求(见第6章,2008版第5章); ——以Q355钢级替代Q345钢级及相关要求(见第7章.9.2,2008版第6章.8.2); ——按不同交货状态规定各牌号的化学成分,并修改了细化晶粒元素的含量(见7.1 ,2008版6.1) ——按不同交货状态规定各牌号的力学性能,并将下屈服强度修改为上屈服强度,其指标相应提高了10 MPa~15 MPa(见7.4.1.7.4.2,2008版6.4.1.6.4.2); —一细化了钢材表面质量要求(见7.5,2008版6.5); ——修改了试验方法和检验规则,明确了冲击试验的取样部位(见第8章、第9章,2008版第7章、第8章); ——增加了本标准牌号与国外标准牌号对照表(见附录A)。本标准由中国钢铁工业协会提出。 本标准H全国钢标准化技术委员会归口(SAC/TC 183)。 本标准起草单位:鞍钢股份有限公司、冶金工业信息标准研究院、首钢总公司河钢股份有限公司唐山分公司、西王特钢有限公司、山东钢铁股份有限公司莱芜分公司、营口中车型钢新材料有限公司、中信金属有限公司。 本标准主要起草人:刘徐源、朴志民、栾燕、载强、师莉、沈钦义、邓翠青、张灵通、赵新华、李文武、王厚昕张成连、高燕。 本标准所代替标准的历次版本发布情况为: 一GB 1591- 1979、GB 1591- 1988、GB/T 1591- 1994 GB/T 1591- -2008。
硬质合金材料及牌号
硬质合金材料及牌号 YG3X 14.6-15.2 1320 92 适于铸铁、有色金属及合金淬火钢合金钢小切削断面高速精加工。K01 YG3X YG6A 14.6-15.0 1370 91.5 适于硬铸铁，有色金属及其合金的半精加工，亦适于高锰钢、淬火钢、合金钢的半精加工及精加工。K05 YG6A YG6X 14.6-15.0 1420 91 经生产使用证明，该合金加工冷硬合金铸铁与耐热合金钢可获得良好的效果，也适于普通铸铁的精加工。K10 YG6X YK15 14.2-14.6 2100 91 适于加工整体合金钻、铣、铰等刀具。具有较高的耐磨性及韧性。K15 K20 YK15 YG6 14.5-14.9 1380 89 适于用铸铁、有色金属及合金非金属材料中等切削速度下半精加工。K20 YG6 YG6X-1 14.6-15.0 1500 90 适于铸铁，有色金属及其合金非金属材料连续切削时的精车，间断切削时的半精车、精车、小断面精车、粗车螺纹、连续断面的半精铣与精铣，孔的粗扩与精扩。K20 YG6X-1 YG8N 14.5-14.8 2000 90 适于铸铁、白口铸铁、球墨铸铁以及铬、镍不锈钢等合金材料的高速切削。K30 YG8N YG8 14.5-14.9 1600 89.5 适于铸铁、有色金属及其合金与非金属材料加工中，不平整断面和间断切削时的粗车、粗刨、粗铣，一般孔和深孔的钻孔、扩孔。K30 YG8 YG10X 14.3-14.7 2200 89.5 适于制造细径微钻、立铣刀、旋转锉刀等。K35 YG10X YS2T 14.4-14.6 2200 91.5 属超细颗粒合金，适于低速粗车，铣削耐热合金及钛合金，作切断刀及丝锥、锯片铣刀尤佳。K30 YS2T YL10.1 14.9 1900 91.5 具有较好的耐磨性和抗弯强度，主要用为生产挤压棒材，适合做一般钻头、刀具等耐磨件。K15-K25 YL10.1 YL10.2 14.5 2200 91.5 具有很好的耐磨性和抗弯强度，主要用来生产挤压棒材，制作小直径微型钻头、钟表加工用刀具，整体铰刀等其它刃具和耐磨零件。 K25-K35 YL10.2 YG15 13.9-14.2 2100 87 适于高压缩率下钢棒和钢管拉伸，在较大应力下工作的顶锻、穿孔及冲压工具。YG15 YG20 13.4-13.7 2500 85 适于制作冲压模具，如冲压手表零件、乐器弹簧片等；冲制电池壳、牙膏皮的模具；小尺寸钢球、螺钉、螺帽等的冲压模具；热轧麻花钻头的压板。YG20 YG20C 13.4-13.7 2200 82 适于制作标准件、轴承、工具等行业用的冷镦、冷冲、冷压模具；弹头对弹壳的冲压模具。YG20C
药芯焊丝牌号对照表
药芯焊丝牌号对照表 Pleasure Group Office【T985AB-B866SYT-B182C-BS682T-STT18】
药芯焊丝牌号对照表 序号符合相当标准GB AWS JIS 结构钢用药芯焊丝 1GB/T 10045-2001 E500T-1 E70T-1Z3313 YFW-C50DR 2GB/T 10045-2001 E501T-1 E71T-1 Z3313 YFW-C50DR 3GB/T 10045-2001 E500T-5 E70T-5Z3313 YFW-C503B 4------------ E81T1-Ni1 Z3313 YFW-C603R 5GB/T 10045-2001 E500T-1 E70T-1Z3313 YFW-C50DR 6---------------------Z3313 YFL-C504R 7---------------------Z3320 YFA-50W 8GB/T 17493-1998 E550T1-W E80T1-W Z3320 YFA-58W 耐热钢用药芯焊丝 9GB/T 17493-1998 E551T1-A1 E81T1-A1Z3318 YFM-C 10GB/T 17493-1998 E551T1-B1 E81T1-B1Z3318 YFCM-C 11GB/T 17493-1998 E551T1-B2 E81T1-B2 Z3318 YF1CM-C 12-------------------------------- 13GB/T 17493-1998 E601T1-B3 E91T1-B3Z3318 YF2CM-C 气保焊不锈钢药芯焊丝 14GB/T 17853-1999 E308T1-1E308T-1Z3323YF308C 15GB/T 17853-1999 E308LT1-1E308LT-1 Z3323YF308LC 16GB/T 17853-1999 E309T0-1 E309T-1Z3323 YF309C 17GB/T 17853-1999 E309LT0-1 E309LT-1Z3323 YF309LC 18GB/T 17493-1999 E309MoT0- 1 ----------Z3323 YF309MoC 19GB/T 17853-1999 E316T0-1 E316T-1 Z3323 YF316C 20GB/T 17853-1999 E316LT0-1 E316LT-1 Z3323 YF316LC 21GB/T 17853-1999 E347T1-1 E347T-1Z3323 YF347C 22GB/T 17853-1999 E410T0-1 E410T-1Z3323 YF410C 23GB/T 17853-1999 E430T0-1 E430T-1Z3323 YF430C 不锈钢TIG焊用药芯焊丝 24(相当)GB/T 17853-1999 E308T1-5 E308T-2Z3323 YF308C 25GB/T 17853-1999 R308LT1-5 E308LT-2Z3323 YF308LC 26(相当)GB/T 17853-1999 E309T1-5 E309T-2Z3323 YF309C
ASTM A242高强度低合金结构钢
高强度低合金结构钢 ASTM A242/242M-04 1 范围 1.1 本标准适用于焊接、铆接和螺栓连接结构用的高强度低合金结构钢型材、钢板和棒材。这些钢材主要用作要求减轻重量或延长使用寿命的构件。该类钢在环境下的耐大气腐蚀性能明显优于含铜或不含铜的碳素结构钢。当完全暴露于大气中时，这种钢可以在裸露（未加涂层）状态下用于许多场合（见注1）。本标准仅适用于厚度≤4英寸［100mm］的材料。 注1：低合金钢耐大气腐蚀性评估方法见G101指南。 1.2 当钢必须焊接时，其先决定条件是采用适合于规定钢级和预定用途的焊接工艺。可焊性资料见A6/A 6M标准中附录X3。 1.3 用英寸——磅单位或用SI 单位表示的数值应视为标准值。本标准中，SI单位用括号示出。每种单位制所表示的数值并非精确相等，因此，每种单位制必须单独使用。混用两种单位制的数值，可能导致与标准不相符合。 1.4 对由卷板制成的钢板，应执行A6/A6M标准中包括的附加测试要求和附加测试结果报告的附加要求。 2 引用文件 2.1 ASTM标准： A6/A6M 结构用轧制钢板、型钢、钢板桩和棒材的一般要求 G101 低合金钢耐大气腐蚀性评估指南 3 一般交货要求 3.1 按本标准供货的钢材应符合现行版本的A6/A6M标准中的相应要求。对于特殊订购的结构钢产品除存在疑议外，此时也是通用的。 3.2 卷板产品不适用于本标准，除非其已压平或切成定尺长度。由卷板制成的钢板指已开卷成单张钢板。该加工过程可直接支付交货，或承担包括钢带卷到加工成结构钢产品在内的各种操作工序。这些操作包括开卷、展开、矫直、热成型或冷成型（如适合的话）、切成定尺钢板、试验、检查、状态、热处理（如适用的话）、包装标志、装运和检验证书。 注2：对于钢带卷制成的结构产品，除热处理或消除应力处理外，对于每种合格的钢带卷应报告两种试验结果。有关钢带卷制成的产品的附加要求列于A6/A6M中。 - 1 -
硬质合金牌号、性能及用途【完整版】
硬质合金牌号、性能及用途【完整版】 硬质合金是以一种或几种难熔碳化物（碳化钨、碳化钛等）的粉末为主要成分，加入作为粘接剂的金属粉末（钴、镍等），经粉末冶金法而制得的合金。它主要用于制造高速切削刃具和硬、韧材料切削刃具，以及制作冷作模具、量具和不受冲击、振动的高耐磨零件。 硬质合金的特点 （1）硬度、耐磨性和红硬性高 硬质合金常温下硬度可达86~93HRA，相当于69~81HRC。在900~1000℃能保持高硬度，并有优良的耐磨性。与高速工具钢相比，切削速度可高4~7倍，寿命长5~80倍，可切削硬度高达50HRC的硬质材料。 （2）强度、弹性模量高 硬质合金的抗压强度高达6000MPa，弹性模量为（4~7）×105MPa，都高于高速钢。但其抗弯强度较低，一般为1000~3000MPa。 （3）耐蚀性、抗氧化性好 一般能很好地抗大气、酸、碱等腐蚀，不易氧化。 （4）线膨胀系数小 工作时，形状尺寸稳定。 （5）成形制品不再加工、重磨 由于硬质合金硬度高并有脆性，所以粉末冶金成形烧结后不再进行切削加工或重磨，特需再加工时，只能采用电火花、线切割、电解磨削等电加工或专门的砂轮磨削。通常由硬质合金制成的一定规格的制品，采用钎焊、粘接或机械装夹在刀体或模具体上使用。 常用硬质合金 常用硬质合金按成分和性能特点分为三类：钨钴类、钨钛钴类、钨钛钽（铌）类。生产中应用最广泛的是钨钴类和钨钛钴类硬质合金。 （1）钨钴类硬质合金 主要成分是碳化钨（WC）和钴，牌号用代号YG（“硬”、“钴”两字汉语拼音字首），后加钴含量的百分数值表示。如YG6表示钴含量为6%的钨钴类硬质合金，碳化钨含量为94%。 （2）钨钛钴类硬质合金 主要成分是碳化钨（WC）、碳化钛（TiC）及钴，牌号用代号YT（“硬”、“钛”两字汉语拼音字首），后加碳化钛含量的百分数值表示。如YT15表示碳化钛含量15%的钨钛钴类硬质合金。 （3）钨钛钽（铌）类硬质合金 这类硬质合金又称通用硬质合金或万能硬质合金，主要成分是碳化钨（WC）、碳化钛（TiC）、碳化钽（TaC）或碳化铌（NbC）和钴组成。牌号用代号YW（“硬”、“万”两字汉语拼音字首）后加序数表示。 表①常用硬质合金的牌号及化学成分
合金钢练习题及参考答案
（合金钢） （一）填空题 1. 根据各种合金元素规定含量界限值，将钢分为、、 三大类。 2. Q235AF表示σs =MPa，质量为级的钢。 3.Q390A表示σs =MPa，质量为级的钢。 4.钢中提高淬透性元素的含量大，则过冷奥氏体，甚至在空气中冷却也能形成马氏体组织，故可称其为空淬钢。 5.高的回火稳定性和二次硬化使合金钢在较高温度（500～600℃）仍保持高硬度（≧60HRC），这种性能称为。 6.易切削钢是指钢中加入S，Pb、等元素，利用其本身或与其他元素形成一种对切削加工有利的化合物，来改善钢材的切削加工性。 7.钢的耐热性是和的综合性能。耐热钢按性能和用途可分为和两类。 8.常用的不锈钢按组织分为、、。 （二）判断题 1.随着合金元素在钢中形成碳化物数量的增加，合金钢的硬度、强度提高，塑性、韧性下降。（） 2.合金元素中的镍、锰等合金元素使单相奥氏体区扩大。（） 3.高速钢的铸态组织中存在莱氏体，故可称为莱氏体钢。（） 4.高熔点的合金碳化物、特殊碳化物使合金钢在热处理时不易过热。（） 5.由于合金钢的C曲线向右移，临界冷却速度降低，从而使钢的淬透性下降。（） 6.Q345钢属于非合金钢。（） 7.合金渗碳钢是典型的表面强化钢，所以钢中含碳量w C＞0.25％。（） 8.截面较大的弹簧经热处理后一般还要进行喷丸处理，使其表面强化。
（） 9.GGr15钢中铬的质量分数为1.5％，只能用来制造滚动轴承。（） 10.20CrMnTi是应用最广泛的合金调质钢。（） （三）选择题 1.钢中的元素引起钢的热脆，钢中元素引起钢的冷脆。 A.Mn B.S C. Si D.P 2.含有Cr、Mn、Mo、W、V的合金钢，经高温奥氏体充分均匀化并淬火后，至500～600℃回火时，硬度回升的现象，称为。 A.回火稳定性 B.回火脆性 C.二次硬化 3.制造截面尺寸在30mm以下的汽车变速齿轮、轴等，选用。 A. 20Cr B.40Cr C.20CrMnTi 4.机床齿轮、轴、汽车半轴，常选用。 A.40Cr B.45 C.35CrMoAl 5.截面较大，形状复杂、工作条件繁重的各种冷冲模用。 A.T12A B.Cr12 C.Cr12MoV D.9Mn2V 6.大多数合金元素都能溶于铁素体，产生固溶强化，使铁素体。 A. 强度、硬度提高 B.塑性下降 C.韧性下降 7.滚动轴承的锻件毛坯必须经处理。 A.正火 B.完全退火 C.球化退火 8.弹簧钢的热处理采用处理。 A.淬火+低温回火 B.调质处理 C.淬火+中温回火 9.冷作模具钢的最终热处理一般为。 A.调质 B.球化退火 C.淬火+低温回火 10.5CrNiMo制造的热锻模最终热处理为。
焊接工艺评定、焊接工艺规程实用编制方法
焊接工艺评定、焊接工艺规程的实用编制方法 一、焊接工艺评定的有关概念 二、焊接工艺评定及使用管理程序 三、焊接工艺评定变素及其评定规则 四、如何阅读焊接工艺评定报告 五、如何编制焊接工艺规程 一、焊接工艺评定的有关概念 1、焊接工艺评定的定义和目的 2、消除焊接工艺评定认识上误区： 3、“焊接性能”与“焊接性” 4、“焊接性能试验”与“焊接工艺评定” 5、“焊缝”与“焊接接头” 6、“焊接工艺评定”与“焊工技能考试” 7、焊接工艺评定的基本条件 8、常用焊接工艺评定标准： JB4708－2000《钢制压力容器焊接工艺评定》 GB50236－98《现场设备、工业管道焊接工程施工及验收规范》第4章 劳部发1996[276]号《蒸汽锅炉安全监察规程》附录I JGJ81-2000《建筑钢结构焊接技术规程》第5章 GB128-90《立式圆筒形钢制焊接油罐施工及验收规范》附录一 ASME第IX卷《焊接与钎焊》 二、焊接工艺评定及使用管理程序 1、焊接工艺评定程序 （1）焊接工艺评定立项 （2）焊接工艺评定委托 （3）编制焊接工艺指导书（WPI）并批准 （4）评定试板的焊接 （5）评定试板的检验 焊接工艺评定失败，重新修改焊接工艺指导书，重复进行上述程序。
（6）编写焊接工艺评定报告（PQR）并批准 2、焊接工艺评定文件的使用与管理 （1）焊接工艺评定文件的受控登记。 （2）焊接工艺评定的有效版本及换版转换。 （3）每季度编制焊接工艺评定文件的有效版本目录。 （4）保证现场工程和产品的焊接工艺评定的覆盖率为100%。 （5）焊接工艺评定文件作为公司的一项焊接技术储备，属于公司重要技术机密文件，应妥善保管。 三、焊接工艺评定变素及其评定规则 1、焊接工艺评定的主要变素： 试件形式 母材类别 焊接方法 焊接工艺因素 焊后热处理种类及参数 母材厚度 焊缝熔敷金属厚度 四、如何阅读焊接工艺评定报告 1、如何认识焊接工艺评定报告的作用 （1）焊接工艺评定报告的合法性： （2）焊接工艺评定报告的有效性： （3）焊接工艺评定报告及焊接工艺规程的局限性： （4）焊接工艺评定报告是一种必须由企业焊接责任工程师和总工程师签字的重要质保文件，也是技术监督部门和用户代表审核施工企业质保能力的主要依据之一。 2、焊接工艺评定报告与焊接工艺规程的关系 3、阅读焊接工艺评定报告的方法 五、如何编制焊接工艺规程 1、焊接工艺规程的作用 2、焊接工艺规程的基本要求 3、焊接工艺规程的编写应遵循的原则
中低合金耐磨钢热处理
中、低合金耐磨钢的热处理 (1)中、低合金铸钢件大多用于汽车、拖拉机等机械工业要求有良好强度和韧性的重要部件。一般来说，对于抗拉强度要求小于650MPa者，施以正火+回火处理；而对于抗拉强度要求大于650MPa者，则采用淬火+回火处理，热处理后组织为回火索氏体。这比正火或退火所得珠光体及铁素体组织具有更高的强度和良好的韧性。这种热处理通常称之为调质处理。但当铸件形状及尺寸不宜淬火时，则宜采用正火+回火取代调质处理，而所得力学性能也较之淬火钢略低。 (2)中、低合金铸钢件在调质处理前最好进行一次正火或正火+回火预处理，以细化晶粒，均匀组织，增加最终调质处理的效果，也有利于减少铸态组织对调质后铸钢性能的影响，以及避免铸件内部铸造应力而导致铸件淬火时变形或开裂的可能性。对于碳的质量分数在0.2%以下的低碳低合金铸钢件调质前可采用正火预处理。 (3)中、低合金铸钢件的淬火处理要求尽可能得到马氏体组织。为此，应根据铸钢的牌号、淬透性和铸件壁厚形状等来选择淬火温度和冷却介质。 (4)中、低合金钢铸件淬火后应立即回火，调整铸钢的淬火组织，以达到所需的综合力学性能要求，同时消除淬火应力，防止淬火铸件变形或开裂。 (5)韧化处理是一种在不降低钢的强度条件F，改善其塑性、韧性的处理工艺。它适用于中碳低合金高强度钢铸件。 1)高温淬火工艺：中碳低合金钢以正常温度淬火后，其组织以片状马氏体为主。提高淬火温度，则淬火后组织中以板条状马氏体为主。其特点是强度高、韧性好，且消除了钢中有害杂质在晶界上的吸附，有利于钢的韧性改善． 2)亚临界(两相)区淬火工艺：低碳低合金铸钢一般采用完全淬火。其淬火组织中常因有沿晶析出的共析铁素体，降低了钢的韧性。而两相区淬火即为在温度Ac1～Acm之间淬火。其淬火组织为马氏体和均匀分布的细小铁素体的复相组织，减少了一般淬火铸钢回火脆性的危险，显著地提高了铸钢的韧性，降低了铸钢的低温脆变温度。低碳钢在双相区淬火并具有铁素体+马氏体组织的称为双相钢。值得注意的是：随着钢中含碳量的增多，双相钢的强度增大，伸长率下降。而与一般双相钢相比较，双相区二次淬火后，钢的强度和塑性同时得到了提高，其中尤其是塑性的提高更为显著。 3)细化或超细化处理：对于高碳低合金过共析铸钢，细化其碳化物，并改善其分布特性，是提高该钢种韧性的有效方法。此工艺特点是采用高温来固溶钢中的过剩碳化物，而后油冷淬火，得到马氏体+残余奥氏体组织，而后在350～450℃回火。得到贝氏体及回火马氏体，并同时得到极细的颗粒状碳化物。以此预处理作为钢最终热处理前的准备，以获得较细颗粒碳化物组织，提高铸钢的性能。 热处理工艺是完成耐磨属性的重要步骤[6]: (1)正火:以80～100℃/h的速度升温,升至860～880℃保温4h后空冷。目的为减少铸造应力,细化组织,为淬火做组织准备。 (2)淬火:在920℃保温2h后,衬板汕淬,锤头局部用模数为2.5～2.6的水玻璃加盆水溶液淬火,以获得马氏体为主要目的。
- GB-T-1591--低合金高强度结构钢
- 低合金高强度结构钢牌号
- 低合金高强度结构钢牌号和性能
- 低合金钢高强度钢板材分层原因分析
- ASTMA242高强度低合金结构钢
- ASTMA242高强度低合金结构钢 (1)
- 低合金高强度结构钢GBT1591-2008
- 低合金高强度钢化学成分.
- 低合金高强度结构钢
- 低合金高强度钢新旧标准对照表
- 低合金高强度结构钢的焊接特点
- (完整word版)GBT1591-2018低合金高强度结构钢
- 低合金高强度结构钢GBT
- GBT 1591-2018低合金高强度结构钢
- (完整word版)GBT1591-2018低合金高强度结构钢
- 低合金高强度结构钢的牌号表示方法和主要技术要求
- 低合金高强度钢技术参数
- GBt1591-94低合金高强度钢
- 低合金高强度结构钢牌号对照表
- (完整版)低合金高强度结构钢GBT1591-2008