1、This document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2014 by Navistar, Inc. AUGUST 2014 Page 1 of 14 NAVISTAR, INC. Material, Parts, and Process Specification
2、s (MPAPS) NUMBER: MPAPS A-0 PART III TITLE: Classification System for Heat Treated Steels CURRENT Rev. No.: 1408 DATE: AUGUST 2014 WRITTEN/REVIEWED BY: Materials Engineering APPROVED BY: Materials Engineering SUPERSEDES: CEMS A-0 Pt III - August 2012 PRINTED COPIES OF THIS DOCUMENT MUST BE VERIFIED
3、FOR CURRENT REVISION This specification may involve hazardous materials, equipment, and procedures. This specification does not purport to address all of the safety issues associated with its use. The user is responsible to consult appropriate safety and health practices and to determine the applica
4、bility of regulatory limits prior to use. Change Notice: Changed to new MPAPS format; removed Table 4 for global steels, and old Table 5 became Table 4; editorial changes. 1.0 SCOPE MPAPS A-0 consists of three major sections: Part I Chemical Composition of Standard Steels Part II System of Steel Cla
5、ssification for Standard Steels Part III Classification System for Heat Treated Steels 1.1 Restricted Chemical Substances Effective January 1, 2007, all product supplied to the requirements of this specification must comply with the requirements of the MPAPS B-50 specification. 2.0 INTRODUCTION MPAP
6、S A-0 Part III defines a system of classifying steels for heat treated applications by carbon content and hardenability, rather than by chemical composition. It can be used for quenched and tempered and carburized and hardened applications. This system should be used on engineering drawings througho
7、ut the Corporation wherever practicable. This system allows the use of optional steels for the manufacture of parts. The major objectives of this specification are: 2.1 To provide manufacturing with a system for the selection of equivalent steels, without the necessity of obtaining the approval of t
8、he controlling Design Engineering department. This allows for optimum use of inventory and will facilitate world-wide design. 2.2 To permit outside suppliers of finished parts the maximum freedom in steel selection consistent with maintaining the required properties. 2.3. To allow development and us
9、e of more economical steels. 3.0 CONTENTS PAGE INTRODUCTION 1 CLASSIFICATION BY STEEL CODE 2 CHEMICAL COMPOSITION AND METALLURGICAL REQUIREMENTS 14 DESIGNATION ON DRAWINGS 15 STEEL ORDERED BY NAVISTAR 15 STEEL ORDERED BY OUTSIDE SUPPLIERS 15 STRAND CAST STEEL USAGE 15 APPENDIX - GENERAL INFORMATION
10、NUMBER: MPAPS A-0 PART III TITLE Classification System for Heat Treated Steels REVISION: 1408 This document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2014 by Nav
11、istar, Inc. AUGUST 2014 Page 2 of 14 4.0 REFERENCE DOCUMENTS Unless otherwise specified, the latest issue of all referenced standards shall apply. The following standards, specifications and regulations are referenced in this specification. Quality System Standard ISO 9001 or TS-16949 ASTM E 112 CFR
12、 Title 29, Part 1910 NAVISTAR CEMS AT-2 NAVISTAR Manufacturing Standard MS-D-13 NAVISTAR CEMS AT-3 NAVISTAR Engineering Procedural Std. EPS-89 ASTM A 255 NAVISTAR Engineering Procedural Std EPS-155 ASTM E 18 NAVISTAR MPAPS B-50 5.0 CLASSIFICATION BY STEEL CODE 5.1 Selection of Steel Code The respons
13、ibility for the selection of a steel code to be shown on the drawing is a function of the controlling design engineering department. It is imperative that Materials Engineering personnel be consulted by the designer before a code is selected. See EPS-89 and EPS-155, Design Control and World Design S
14、tandards and Control, respectively. For the selection of a particular steel within the required code, see “Steel Ordered by Navistar Operations,” Section 10.1, or “Steel Ordered by Outside Suppliers,” Section 10.2. The basis for the classification system is the hardness-distance relationship as meas
15、ured on a standard end quench test specimen (Jominy bar). Many standard steels have published hardenability bands which represent data from a large number of heats. Selection of the carbon content and the hardenability required will define the steels that can be used. Steels with equivalent carbon c
16、ontent and hardenability will essentially have the same Jominy bar hardness-distance relationship. 5.2 Hardenability Criteria The primary hardenability criterion used is the distance corresponding to the hardness of a 50% martensitic structure. This structure is more indicative of the comparative ha
17、rdenability characteristics of steels than other percentages of martensite. However, provision is made for the use of criteria other than 50% martensite where required. 5.3 Description Of Code This coding system for heat treated steels consists of two parts: carbon content and hardenability requirem
18、ents. An example of the code would be: C34-51E4-32 where the term “C34-51” indicates the allowable carbon content range (0.34 to 0.51%) and “E4-32” describes the hardenability requirements (50% martensite hardness values) in terms of Jominy bar (J) distances (4/16 to 32/16 inch). An “E” prefix indic
19、ates that the “J” distances are in 1/16 inch customary U.S. units; whereas, an “M” prefix would mean the “J” distances are in mm (metric units). 5.3.1 The code system describes four points on a hardenability plot. The first two points are related to the carbon range shown in the code and indicates t
20、he minimum and maximum RC hardness at J = 1/16 NUMBER: MPAPS A-0 PART III TITLE Classification System for Heat Treated Steels REVISION: 1408 This document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission from Corporate Technical Standards. Suppliers are requi
21、red to assume all patent liability. 2014 by Navistar, Inc. AUGUST 2014 Page 3 of 14 inch (or 1.5 mm). Values are listed in Table 1 for carbon contents thru 0.65%. The other two points represent hardenability limits at J distances beyond 1/16 inch (or 1.5 mm) as shown in the second part of the code.
22、A minimum hardness as related to the minimum carbon content is designated at the first J distance and a maximum hardness as related to the maximum carbon content is designated at the second J distance. Hardness values for these J distances are related to percent martensite in the heat treated struct
23、ure and will vary according to the coding criteria used for a given application. Values for various percents martensite versus carbon content, through 0.70% Carbon, are listed in Tables 1 and 2. 5.3.2 Figure 1 illustrates a plot of the four points, based on 50% martensite, described by the example:
24、C34-51E4-32 (See Table 1 for values.) Figure 1 - Example Plot of C34-51E4-32 5.3.3 When desired to include free machining steels, the code may be modified to include an “F” suffix letter, e.g., C34-51E4-32F. See “Chemical Composition,” page 14. Numbers appearing in parentheses after the “J” distance
25、 number in this example, either after the 4 and/or 32, indicate minimum RC hardness for the 4/16 position and maximum RC hardness for the 32/16 position. NOTE: Utilization of this coding system in specifying heat treated steels must be used in conjunction with a specific heat treatment note applied
26、to the individual piece part drawing. It is to be recognized that this combination of material code and heat treat note is designed to provide the desired mechanical properties in the finished piece part. A change in material, even within a given code, may require an adjustment to the heat treat pro
27、cess. 5.4 Coding Criteria 5.4.1 50% Martensite The 50% martensite microstructure criteria as associated with DI (Ideal Critical Diameter) is the most common indicator for comparing hardenability characteristics of steels. This is the primary method for selecting a code for heat treated steels and sh
28、ould be used wherever possible to allow the largest latitude in material sections. An example of a code thus selected is: 202530354050556065455 15 25 30 5045403520101 2 4 6 8 10 12 14 16 18 20 24 26 28 30 32XXXXR C 47 maxa t J = 23/16inchR C 64 maxa t J = 1/16 i nc hR C 52 maxa t J = 1/16 i nc hR C
29、40 maxa t J = 4/16 i nc hHARDNESS, ROCKWELL CDI S TAN C E F OR QU ENCHE D EN D, MI LLI METERS22THDI S TAN C E F OR QU ENCHE D EN D, 1/16 I NCHNUMBER: MPAPS A-0 PART III TITLE Classification System for Heat Treated Steels REVISION: 1408 This document is restricted and may not be sent outside Navistar
30、, Inc. or reproduced without permission from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2014 by Navistar, Inc. AUGUST 2014 Page 4 of 14 C 3 4 -5 1 E 4 -3 2C arb on R an ge Hard en ab i l i ty R an geI n d i cates li m i ts o f carb on con ten t.A l s o es t
31、a b l i s h es m i n i m u m a n d m a x i -m u m h ard n es s a t J 1 fro m m i n a n dm a x C ( s ee T ab l e 1)1).For ex a m p l e s h ow n :C = 0 .3 4 - 0. 5 1R C 52 m i n a t J = 1 / 16 i n chRC 64 m ax a t J = 1 / 16 i n chI n d i cates req u i re m e n ts f or h ard en ab i l i ty li m i tsb
32、as ed o n 5 0% m arten s i te m i cros tru ctu re an ds p eci fie d carb on ran ge. Fi rs t n u m b er (4) i n d i -cates m i n i m u m Jo m i n y b ar d i s ta n ce re q u i red f orh ard n es s corres p on d i n g to 5 0% m arten s i te s tru c-tu re for m i n i m u m carb on ( 0. 34% ) con ten t
33、(f romT ab l e 1) . S econ d n u m b er (32 ) i n d i cates m axi m u mJ d i s ta n ce for h ard n es s corres p on d i n g to 5 0%m arten s i te s tru ctu re for m axi m u m carb on con ten t(0 .5 1% ) ( from T ab l e 1)1).For ex a m p l e s h ow n :R C 4 0 m i n a t J = 4 / 16 i n chR C 4 7 m ax a
34、 t J = 32/16 in ch5.4.2 Figure 2 shows a plot of the four points defined by the example C34-51E4-32. The hardenability band for 8640H is also plotted to demonstrate its compliance with this code. The complete band of the following steels also comply with this code: 15B41H, 4140H, 5140H and 8740H. Fi
35、gure 2 - Example C34-51E4-32 and 8640H Band 5.5 Hardness At A Jominy Distance When a given application requires a specific minimum tensile strength in excess of what the 50% martensite criteria would indicate, the code can be modified to reflect these requirements at some location in the piece part.
36、 This is achieved by noting the hardness corresponding to the required as quenched tensile strength in parentheses following the specified minimum J distance in the code. The J distance shown in the code is to reflect the Jominy equivalent cooling rate at the critical location in the piece part. An
37、example of this type of code is: 145 10 15 20 25 30 35 40 45 501 2 4 6 8 10 12 16 18 20 22 24 26 28 30 3220253035404550556065HARDNESSROCKWELLCD I S TA N C E FR M QU E N C H E D E N D , M I L L I M E TE R SD I S TA N C E FR OM QU E N C H E D E N D , 1 / 1 6 TH I N C HXXXXR C 5 2 m ina t J =1 / 1 6 in
38、c hR C 6 4 m a xa t J =1 / 1 6 inc hR C 4 7 m a xa t J =3 2 / 1 6 inc hR C 4 0 m ina t J =4 / 1 6 inc hNUMBER: MPAPS A-0 PART III TITLE Classification System for Heat Treated Steels REVISION: 1408 This document is restricted and may not be sent outside Navistar, Inc. or reproduced without permission
39、 from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2014 by Navistar, Inc. AUGUST 2014 Page 5 of 14 C 34- 51E 4 (45 )- 3 2C a r b o n R a n g e H a r d e n a b ili ty R a n g eSa m e a s p r e v io u s e x a m p l e :C = 0 . 3 4 - 0 .5 1RCRC 6 4 m a x a t J =
40、1 /1 6 i n c hJ = 4 /1 6 i n c h i n th is e x a m p l e r e pr e s e n t s th ec o o li n g r a te a t t h e c r itic a l lo c a tion o n t h e p ie c ep a r t a nd R C 4 5 c o r r e s po n d s t o th e m i n i m u m a sq ue nc he d te n s ile st r e n g th ne c e s s a r y to pr o v ideth e m i n
41、i m u m te m pe r e d te n s ile st r e n g th a t th a tp o i n t .A t J = 3 2 /1 6 i n c h the ha r d ne s s c o r r e s po nd s t oa 5 0 % m a r t e n s it e st r uc tur e fo r th e m a x c a r bo no f th e s p e c ifie d r a n g e (s a m e c r ite r ia a s fir s te x a m p l e .)5 2 m i n a t J
42、= 1 / 1 6 in c h5.5.1 Figure 3 shows a plot of the four points defined by the second example, C34-51E4(45)-32. The hardenability band for 4140H is also plotted to demonstrate its compliance with this code requiring hardness at a specified distance. The complete band of the following steels also comp
43、lies with this code: 4137H, 15B41, 8340H and 5140H. Figure 3 - Example C34-51E4(45)-32 and 4140H Band 5.6 Hardness And Microstructure At A Jominy Distance Other applications, for fatigue or other reasons, may require microstructure controls as well as strength requirements at some location in the pi
44、ece part. The code can also be written to accommodate these needs. In these applications where an 80% or more martensitic structure is required, the recommended carbon range is limited to a 12 point spread (see discussion in Appendix for recommended carbon ranges). The minimum J distance shown in th
45、e code should reflect the Jominy equivalent cooling rate at the critical location on the piece part where the desired strength and microstructure are needed. A satisfactory code is developed by selecting the hardness corresponding to the desired percent martensitic structure for the midpoint carbon
46、content of the specified carbon range and noting it in parentheses next 141 2 4 6 8 10 12 16 18 20 22 24 26 28 30 3220253035404550556065HARDNESSROCKWELLCD I S TA N C E FR M QU E N C H E D E N D , M I L L I M E TE R SD I S TA N C E FR OM QU E N C H E D E N D , 1 / 1 6 TH I N C HXXXXR C 5 2 m ina t J
47、=1 / 1 6 inc hR C 6 4 m a xa t J =1 / 1 6 inc hR C 4 7 m a xa t J =3 2 / 1 6 inc hR C 4 5 m ina t J =4 / 1 6 inc h5 10 15 20 25 30 35 40 45 50NUMBER: MPAPS A-0 PART III TITLE Classification System for Heat Treated Steels REVISION: 1408 This document is restricted and may not be sent outside Navistar
48、, Inc. or reproduced without permission from Corporate Technical Standards. Suppliers are required to assume all patent liability. 2014 by Navistar, Inc. AUGUST 2014 Page 6 of 14 to the minimum J distance requirement. Table 2 lists hardnesses versus carbon content for 80, 90, 95, and 99.9% martensite microstructures. An example of this type of code is: C34-46E4(50)-32 C a r b on R an ge H a r d e n ab ilit y R a n geT w e lv e p o i n t r an ge s e le c t e d :C = 0. 34 - 0 .4 6R C 52 m i n a t J = 1/ 16 in c hRC 6
