1、SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirelyvoluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefro
2、m, is the sole responsibility of the user.”SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions.QUESTIONS REGARDING THIS DOCUMENT: (412) 772-8512 FAX: (412) 776-0243TO PLACE A DOCUMENT
3、 ORDER; (412) 776-4970 FAX: (412) 776-0790SAE WEB ADDRESS http:/www.sae.orgCopyright 1970 Society of Automotive Engineers, Inc.All rights reserved. Printed in U.S.A.SURFACEVEHICLE400 Commonwealth Drive, Warrendale, PA 15096-0001INFORMATIONREPORTSubmitted for recognition as an American National Stand
4、ardJ437aREV.APR70Issued 1949-01Revised 1970-04Superseding J437a MAY69SELECTION AND HEAT TREATMENT OF TOOL AND DIE STEELSForewordThis Document has not changed other than to put it into the new SAE Technical Standards BoardFormat.1. ScopeThe information in this report covers data relating to SAE J438,
5、 Tool and Die Steels, and is intendedas a guide to the selection of the steel best suited for the intended purpose and to provide recommended heattreatments and other data pertinent to their use.Specific requirements as to physical properties are not included because the majority of tool and die ste
6、els areeither worked or given special heat treatments by the purchaser. The purchaser may or may not elect to usethe accompanying data for specification purposes.2. References2.1 Applicable PublicationThe following publication forms a part of the specification to the extent specifiedherein. Unless o
7、therwise indicated the lastest revision of SAE publications shall apply.2.1.1 SAE PUBLICATIONAvailable from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001.SAE J438Tool and Die Steels2.1.2 ASM PUBLICATIONATTN: MSC/Book Order, ASM International, PO Box 473, Novelty, OH 44072-9901.ASM Handbook1
8、948 Edition, pp. 658-6593. The Selection of Tool and Die Steels1Simplification of the problems connected with the selection of tool steels has long been an aim of bothproducers and consumers. This article is restricted to a discussion of the general principles involved inselection and will include a
9、 tabulation of the metallurgical characteristics of the principal tool steel types as anaid in selection. A correlation of these metallurgical characteristics with the requirements of the tool inoperation should form the basis of a sound approach to the selection of a steel for any application. Tabl
10、e 1.1. Condensed from the ASM Handbook, 1948 edition, pp. 658659, with the permission of the American Society for Metals.SAE J437a Revised APR70-2-TABLE 1COMPARISON OF TOOL STEELS ON BASIS OF PROPERTIES AFFECTING SELECTIONSAE Steel DesignationNondeformingPropertiesSafety inHardeningDepth ofHardening
11、 (1)1. These are intended to emphasize major differences between the groups of steels and do not account for the minor differences in depths of hardening that exist between steels of the same group. This is particularly true of the Water Hardening W Steels which are frequently furnished with varying
12、 degrees of hardenability as listed in Table 1.ToughnessResistance toSofteningEffect of HeatWearResistance MachinabilityWater Hardening Tool SteelsW108 Poor Fair Shallow Good(2)2. Toughness decreases somewhat with increasing depth of hardening.Poor Fair BestW109 Poor Fair Shallow Good(2) Poor Fair B
13、estW110 Poor Fair Shallow Good(2) Poor Good BestW112 Poor Fair Shallow Good(2) Poor Good BestW209 Poor Fair Shallow Good Poor Fair BestW210 Poor Fair Shallow Good Poor Good BestW310 Poor Fair Shallow Good Poor Good BestShock Resisting Tool SteelsS1Chromium-Tungsten Fair Good Medium Good Fair Fair Fa
14、irS2Silicon-Molybdenum W Poor(3)3. W as shown here indicates water quench. O as shown here indicates oil quench.W Poor(3) Medium Best Fair Fair GoodO Fair(3) O Good(3)S5Silicon-Manganese W Poor(3) W Poor(3) Medium Best Fair Fair FairO Fair(3) O Good(3)Cold Work Tool SteelsOil Hardening TypesO1Low Ma
15、nganese Good Good Medium Fair Poor Good GoodO2High Manganese Good Good Medium Fair Poor Good GoodO6Molybdenum Graphitic Fair Good Medium Fair Poor Good BestMedium Alloy Air Hardening TypesA25% Chromium Air Hard Best Best Deep Fair Fair Good FairHigh Carbon-High Chromium TypesD2High Carbon-High Chrom
16、ium (Air) Best Best Deep Fair Fair Best PoorD3High Carbon-High Chromium (Oil) Good Good Deep Poor Fair Best PoorD5High Carbon-High Chromium-Cobalt Best Best Deep Fair Fair Best PoorD7High Carbon-High Chromium-High Vanadium Best Best Deep Poor Fair Best PoorHot Work Tool SteelsChromium Base TypesH11C
17、hromium-Molybdenum-V Good Good Deep Good Good Fair FairH12Chromium-Molybdenum-Tungsten Good Good Deep Good Good Fair FairH13Chromium-Molybdenum-VV Good Good Deep Good Good Fair FairTungsten Base TypesH21Tungsten Good Good Deep Good Good Fair FairHigh Speed Tool SteelsTungsten Base TypesT1Tungsten 18
18、-4-1 Good Good Deep Poor Good Good FairT2Tungsten 18-4-2 Good Good Deep Poor Good Good FairT4Cobalt-Tungsten 18-4-1-5 Good Fair Deep Poor Best Good FairT5Cobalt-Tungsten 18-4-2-8 Good Fair Deep Poor Best Good FairT8Cobalt-Tungsten 14-4-2-5 Good Fair Deep Poor Best Good FairMolybdenum Base TypesM1Mol
19、ybdenum 8-2-1 Good Fair Deep Poor Good Good FairM2Molybdenum-Tungsten 6-6-2 Good Fair Deep Poor Good Good FairM3Molybdenum-Tungsten 6-6-3 Good Fair Deep Poor Good Best FairM4Molybdenum-Tungsten 6-6-4 Good Fair Deep Poor Good Best FairSpecial Purpose Tool SteelsLow Alloy TypesL6Nickel-Chromium Fair G
20、ood Medium Fair Poor Fair FairL7Chromium Fair Good Medium Fair Poor Good FairSAE J437a Revised APR70-3-Practical experience indicates that in the majority of instances the choice is not limited to a single type of toolsteel or even to a particular family of tool steels for a workable solution to an
21、individual tooling problem.Because it is desirable to select the steel that will give the most economical overall performance, the tool lifeobtained with each steel under consideration should be judged by weighing such factors as expectedproductivity, ease of fabrication, and cost.The majority of to
22、ol steel applications can be divided into a small number of groups or types of operations:cutting, shearing, forming, drawing, extrusion, rolling, and battering. Cutting tools include drills, taps,broaches, hobs, lathe tools, and the like. Shearing tools include shears, blanking and trimming dies, p
23、unches,and such. Forming tools include draw, forging, cold heading, and die casting dies. Battering tools includechisels and all forms of tools involving heavy shock. Many of these classifications can be further divided intocold and hot working tools.For each of these groups, certain metallurgical c
24、haracteristics are of utmost importance. Most cutting toolsrequire high hardness, high resistance to the softening effect of heat, and high wear resistance. Shearing toolsrequire high wear resistance combined with fair toughness, and these characteristics must be properlybalanced depending on the to
25、ol design, thickness of stock being sheared, and temperature of the shearingoperation. Forming tools must possess high wear resistance or high toughness and high strength, and manyrequire maximum resistance to heat softening. In battering tools high toughness is most important.Hardness, strength, to
26、ughness, wear resistance, and resistance to heat softening are, therefore, primeselective factors for tool steel applications. Many other properties must be seriously considered in individualapplications; these include permissible distortion in hardening, permissible surface decarburization,hardenab
27、ility or depth of hardness desired, resistance to heat checking, machinability and grindability, as wellas heat treating requirements, including temperatures, atmospheres, and equipment.Table 1 lists those properties which merit special consideration when selecting steels for any application, fromth
28、e list shown. For compositions of these steels, Table 1 of SAE J438.Table 2 is presented as an aid in the relative evaluation of those properties which must be considered for theproper heat treatment of the steels.4. Relation of Design to Heat TreatmentThe design bears, in many ways, upon the servic
29、eability of the toolor machine part, and unsatisfactory performance may frequently be traced directly to faulty design. Thisdiscussion is concerned only with design as it affects the heat treating operation and, through the heattreatment, the serviceability of the finished part. It is the purpose of
30、 this discussion to bring about a bettermutual understanding between the designer and the steel treater so that faulty design which may causecracking or distorting during heat treating can be avoided.The fundamental principles of good design from a heat treatment standpoint are quite simple. Heat tr
31、eatedsteel has a certain strength depending upon the analysis of the steel, the quality of the metal, and the heattreatment which it has received. When subjected to a combination of forces its ultimate strength, the steelcracks or fails. There are 2 types of force combining to break steel, which are
32、:a. The internal stress set up during fabrication and heat treatment of the tool.b. The external force of service.Sometimes the internal stresses alone exceed the strength of the metal, and the parts crack in hardening.Again, the internal stresses may equal 90% or more of the total strength, in whic
33、h case failure will develop inservice under relatively light loads. It therefore appears that the useful strength of a part decreases inproportion as the internal stresses increase.SAE J437a Revised APR70-4-TABLE 2APPROXIMATE COMPARISON OF TOOL AND DIE STEELS ON BASIS OF SOME HEAT TREATING CHARACTER
34、ISTICSSAE Steel DesignationQuenchMediumPreheatTemperature,FHardeningTemperatureRange, (1) F1. The purpose of these columns is to show the usual ranges of temperature employed in hardening and tempering and is not to be used as a specification.HardnessafterQuenching,Rockwell CTemperingTemperatureRang
35、e, (1) FHardnessafterTempering,Rockwell CDecarburization(Prevention ofDuring HeatTreatment)Water Hardening Tool SteelW108 Water (2)2. For large tools and tools having intricate sections, preheating at 1050 to 1200 F is recommended.14201450 6567 350525 65-56 (3)3. Use moderately oxidizing atmosphere
36、in fumace or a suitable neutral salt bath.W109 Water (2) 14201450 6567 350525 65-56 (3)W110 Water (2) 14201450 6567 350525 65-56 (3)W112 Water (2) 14201500 6567 350525 65-56 (3)W209 Water (2) 14201500 6567 350525 65-56 (3)W210 Water (2) 14201500 6567 350525 65-56 (3)W310 Water (2) 14201500 6567 3505
37、25 65-56 (3)Shock Resisting Tool SteelsS1Chromium-Tungsten Oil 12001300 16501800 5759 3001000 57-45 (4)4. Use protective pack from which volatile matter has been removed, carefully balanced neutral salt bath, or atmosphere controlled furnaces. In the latter case, the furnace atmosphere should be in
38、equilibrium with the carbon content of the steel being treated. Furnace atmosphere dew point is considered a reliable method for measuring and controlling this equilibrium.S2Silicon-Molybdenum Water (2) 15501575 6062 300500 60-54 eOil (2) 16001625 5860 300500 58-54 eS5Silicon-Manganese Water (2) 155
39、01600 6062 300650 60-54 eOil (2) 16001675 5860 300650 58-54 eCold Work Tool SteelsOil Hardening TypesO1Low Manganese Oil (2) 14501500 6365 300800 62-50 eO2High Manganese Oil (2) 14201450 6365 375500 62-57 eO6Molybdenum Graphitic Oil (2) 14501500 6365 300800 63-50 eMedium Alloy Air Hardening TypesA25
40、% Chromium Air Hard Air 12001300 17251775 6163 400700 60-57 (4)High Carbon-High Chromium TypesD2High Carbon-High Chromium Air 12001300 18001875 6163 400700 60-58 (4)D3High Carbon-High Chromium Oil 12001300 17501800 6264 400700 62-58 (4)D5High Carbon-High Chromium-Cobalt Air 12001300 18001875 6062 40
41、0700 59-57 (4)D7High Carbon-High Chromium-High Vanadium Air 12001300 18501950 6365 300500 65-63 (4)8501000 62-58Hot Work Tool SteelsChromium Base TypesH11Chromium-Molybdenum-Y Air 14501500 18251875 5355 10001100 51-43 (4)H12Chromium-Molybdenum-Tungsten Oil, Air 14501500 18001900 5355 10001100 51-43
42、(4)H13Chromium-Molybdenum-VV Air 14001450 18251875 5355 10001100 51-43 (4)Tungsten Base TypesH21Tungsten Oil, Air 15001550 21002150 5052 9501150 50-47 (4)High Speed Tool SteelsTungsten Base TypesT1Tungsten 18-4-1 Oil, Air, Salt 15001550 23002375 6365 10251100 65-63 (4)T2Tungsten 18-4-2 Oil, Air, Sal
43、t 15001550 23002375 6365 10251100 65-63 (4)T4Cobalt-Tungsten 18-4-1-5 Oil, Air, Salt 15001550 23002375 6365 10251100 65-63 (4)T5Cobalt-Tungsten 18-4-2-8 Oil, Air, Salt 15001550 23002400 6365 10501100 65-63 (4)T8Cobalt-Tungsten 14-4-2-5 Oil, Air, Salt 15001550 23002375 6365 10251100 65-63 (4)Molybden
44、um Base TypesM1Molybdenum 8-2-1 Oil, Air, Salt 14001500 21502250 6365 10251050 65-63 (4)M2Molybdenum-Tungsten 6-6-2 Oil, Air, Salt 14501500 21752250 6365 10251075 65-63 (4)M3Molybdenum-Tungsten 6-6-3 Oil, Air, Salt 14501500 21502225 6365 10251075 65-63 (4)M4Molybdenum-Tungsten 6-6-4 Oil, Air, Salt 1
45、4501500 21502225 6365 10251075 65-63 (4)Special Purpose Tool SteelsLow Alloy TypesL6Nickel-Chromium Oil (2) 15001600 6264 400800 62-48 (3)L7Chromium Oil (2) 15251550 6365 350500 62-60 (3)SAE J437a Revised APR70-5-Internal stresses arise from many causes, but the most serious by far are those develop
46、ed by differentialcooling resulting from quenching. This differential cooling is largely a function of the size and shape of thepiece being quenched; in other words, the design. Here, then, is the relation of design to heat treatment, andthe basic principle of successful design is to plan shapes whi
47、ch allow the piece to cool as uniformly as possibleduring quenching.Some shapes are almost impossible to harden because of the abruptness in the change of sections, but acertain latitude in design is recognized when using an oil hardening or air hardening steel.Errors in design reach further than me
48、rely affecting the internal stress of hardening. A sharp angle serves toconcentrate greatly the stresses of service. The design of the part may be entirely responsible forconcentrating the service stresses at a point already weakened by internal stresses produced duringhardening.Reducing all the for
49、egoing to a single statement, a part is properly designed from the standpoint of heattreatment when the entire piece may be heated and cooled at approximately the same rate during the heattreating operation. Perfection in this regard is unattainable because, even in a sphere, the surface cools morerapidly than the interior. The designer should, however,
