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 entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising theref
2、rom, 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. Copyright 2010 SAE International All rights reserved. No part of this publication ma
3、y be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: 724-776-4970 (outside USA)
4、Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/J1868_201002SURFACEVEHICLESTANDARDJ1868 FEB2010 Issued 1988-02Revised 2010-02 Superseding J1868 SE
5、P1993 Restricted Hardenability Bands for Selected Alloy Steels RATIONALEPage 2 Item 6 Grain Size: Deleted SAE J418 because SAE cancelled that specification in May 1999. Replaced it with equivalent ASTM specification E 112. Page 4 Note 3: Deleted all references to tables because they are currently un
6、der review and have not been balloted. Left in reference to SAE J409. Added ASTM E 112 to section 2.1.2. 1. SCOPE Restricted hardenability steels have been in use for some time but the specific restrictions for a particular grade depend upon customer needs and vary from mill to mill. Such steels are
7、 desirable to provide more controlled heat treatment response and dimensional control for critical parts. Because of increasing interest in steels with restricted hardenability, the SAE Iron and Steel Technical Committee directed Division 8 to prepare a set of standard steels with restricted hardena
8、bility.In 1993, the American Society for Testing and Materials (ASTM) adopted the twelve SAE restricted hardenability steels and added ten more. SAE decided to include in SAE J1868 the additional 10 steels. In general, steels with restricted hardenability (RH steels) will exhibit a hardness range no
9、t greater than 5 HRC at the initial position on the end-quench hardenability bar and not greater than 65% of the hardness range for standard H-band steels (see SAE J1268) in the “inflection“ region. Generally the restricted hardenability band follows the middle of the corresponding standard H-band.
10、An example of the RH band compared with the standard H-band is given for SAE 4140 in Figure 1. 2. REFERENCES 2.1 Applicable Publications The following publications form a part of this specification to the extent specified herein. The latest issue of SAE publications shall apply. SAE J1868 Revised FE
11、B2010 Page 2 of 282.1.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org.SAE J404 Chemical Compositions of SAE Alloy Steels SAE J406 Methods of Determining Harden
12、ability of Steels SAE J409 Product AnalysisPermissible Variations from Specified Chemical Analysis of a Heat or Cast of Steel SAE J1268 Hardenability Bands for Carbon and Alloy H Steels 2.1.2 ASTM Publications Available from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken
13、, PA 19428-2959, Tel: 610-832-9585, www.astm.org.ASTM A 914 Standard Specification for Steel Bars Subject to Restricted Hardenability Requirements ASTM E 112 Standard Test Methods for Determining Average Grain Size 3. GRADES OF STEEL The RH steels and their corresponding minimum and maximum composit
14、ion limits are shown in Table 1 for a group of 22 alloy steels covering a nominal carbon content range of 0.10 to 0.60%. As the need arises for restricted hardenability in other grades, they will be added to the standard. 4. CHEMICAL COMPOSITION LIMITS To meet restricted hardenability, yet provide f
15、lexibility for producers, composition limits are the same as those given in SAE J404. (These limits are somewhat narrower than allowed for standard H-steels.) It should be understood that alloys which satisfy the restricted hardenability band will fall within SAE J404 composition limits, but not all
16、 steels melted to the composition limits would meet the required RH-band. The limits are given in Table 1, and as indicated in the footnotes, are subject to permissible variations for product analysis and may contain certain levels of elements not specified. 5. IDENTIFICATION As a means of identifyi
17、ng steels specified to restricted hardenability band limits, the suffix letters RH have been added to the conventional series number. It is important that steel consumers use this special identifying designation in specification requirements, as there is no other means of determining when restricted
18、 hardenability band limits apply. When the special identification is used, the steel shall conform to all conditions pertaining to chemical composition limits, restrictions, testing technique, and so forth, as outlined herein. 6. GRAIN SIZE The limits set forth for RH-bands are intended to apply to
19、steels exhibiting a fine austenitic grain size (ASTM No. 5 or finer; see ASTM E 112). SAE J1868 Revised FEB2010 Page 3 of 287. USE OF RESTRICTED HARDENABILITY LIMITS For specification purposes, one must use the tabulated values of Rockwell hardness (HRC) as a function of distance from the quenched e
20、nd of the hardenability bar, either in metric (SI) units (millimeters) or U.S. customary units (sixteenths of an inch). Values below 20 HRC are not specified because such values are not as accurate. Band limits are also shown graphically and are so depicted for convenience in estimating the hardness
21、 values at various intermediate locations on the end quench test bar and for quick comparisons of the various RH grades. The values of Approximate Diameter of Rounds with Same As-Quenched Hardness shown above each RH-band, were selected from the ranges appearing in Figure 7 of SAE J406. The RH-bands
22、 are presented graphically, with distances from the quenched end in both metric (SI) units and U.S. customary units. The hardenability testing technique used as a basis for acceptance shall be in accordance with SAE J406. For specification purposes, RH-band steels shall be within the minimum and max
23、imum HRC range specified at the J1 (J1.5 mm) position and shall meet one additional minimum and one additional maximum HRC value. In this specification, the two additional hardness values shall represent the approximate hardness for 50% martensite for the minimum and maximum specified carbon content
24、, respectively (except where hardenability is too high to exhibit 50% martensite hardness; then the additional two control hardness points shall be 5 HRC below the minimum and maximum hardness specified at the J1 (J1.5 mm) position). In general, these points define the critical locations of the Jomi
25、ny hardenability band for purposes of characterizing heat treatment response. The four specification points are circled in the tables of hardness versus Jominy distance and on the RH-bands. For a portion of the curve not exceeding 5 mm or 3/16 in (not including the control points), a tolerance of tw
26、o points HRC is permitted. For example, referring to the right-hand hardness limit table in Figure 1, a hardenability test bar of a steel meeting the requirements for 4140RH must exhibit a hardness at J1 not less than 54 HRC nor more than 59 HRC. At J12, the test bar must exhibit hardness not less t
27、han 43 HRC, but the maximum hardness can be as high as 52 HRC (or even 54 HRC if this region of the test bar is chosen as the exception). At J20, the bar must exhibit hardness not greater than 47 HRC, but the minimum hardness can be as low as 37 HRC (or as low as 35 HRC if this region of the test ba
28、r is chosen as the exception).(A similar example, for 4140RH with distances from the quenched end in millimeters, would limit hardness at J1.5 mm to not less than 54 HRC nor more than 59 HRC. At J20 mm, the test bar must exhibit hardness not less than 42 HRC. At J30 mm, the test bar must exhibit har
29、dness not greater than 48 HRC.) SAE J1868 Revised FEB2010 Page 4 of 28TABLE 1 - COMPOSITIONS OF RESTRICTED HARDENABILITY STEELS SAESteel No. Ladle Chemical Composition,Weight %(1)(2)(3)CLadle ChemicalComposition,Weight %(1)(2)(3)MnLadle Chemical Composition,Weight %(1)(2)(3)SiLadle ChemicalCompositi
30、on,Weight %(1)(2)(3)NiLadle Chemical Composition,Weight %(1)(2)(3)CrLadle ChemicalComposition,Weight %(1)(2)(3)MoSAE 15B21RH(4)0.17/0.22 0.80/1.10 0.15/0.35 SAE 15B35RH(4)0.33/0.38 0.80/1.10 0.15/0.35 SAE 3310RH 0.08/0.13 0.40/0.60 0.15/0.35 3.25/3.75 1.40/1.75 SAE 4027RH 0.25/0.30 0.70/0.90 0.15/0.
31、35 - - 0.20/0.30 SAE 4118RH 0.18/0.23 0.70/0.90 0.15/0.35 - 0.40/0.60 0.08/0.15 SAE 4120RH 0.18/0.23 0.90/1.20 0.15/0.35 - 0.40/0.60 0.13/0.20 SAE 4130RH 0.28/0.33 0.40/0.60 0.15/0.35 - 0.80/1.10 0.15/0.25 SAE 4140RH 0.38/0.43 0.75/1.00 0.15/0.35 - 0.80/1.10 0.15/0.25 SAE 4145RH 0.43/0.48 0.75/1.00
32、0.15/0.35 - 0.80/1.10 0.15/0.25 SAE 4161RH 0.56/0.64 0.75/1.00 0.15/0.35 - 0.70/0.90 0.25/0.35 SAE 4320RH 0.17/0.22 0.45/0.65 0.15/0.35 1.65/2.00 0.40/0.60 0.20/0.30 SAE 4620RH 0.17/0.22 0.45/0.65 0.15/0.35 1.65/2.00 - 0.20/0.30 SAE 4820RH 0.18/0.23 0.50/0.70 0.15/0.35 3.25/3.75 - 0.20/0.30 SAE 50B4
33、0RH(4)0.38/0.43 0.75/1.00 0.15/0.35 - 0.40/0.60 SAE 5130RH 0.28/0.33 0.70/0.90 0.15/0.35 - 0.80/1.10 - SAE 5140RH 0.38/0.43 0.70/0.90 0.15/0.35 - 0.70/0.90 - SAE 5160RH 0.56/0.64 0.75/1.00 0.15/0.35 - 0.70/0.90 - SAE 8620RH 0.18/0.23 0.70/0.90 0.15/0.35 0.40/0.70 0.40/0.60 0.15/0.25 SAE 8622RH 0.20/
34、0.25 0.70/0.90 0.15/0.35 0.40/0.70 0.40/0.60 0.15/0.25 SAE 8720RH 0.18/0.23 0.70/0.90 0.15/0.35 0.40/0.70 0.40/0.60 0.20/0.30 SAE 8822RH 0.20/0.25 0.75/1.00 0.15/0.35 0.40/0.70 0.40/0.60 0.30/0.40 SAE 9310RH 0.08/0.13 0.45/0.65 0.15/0.35 3.00/3.50 1.00/1.40 0.08/0.15 Restricted Hardenability Limits
35、for Steels in Table 1 appear in Figures 2 through 23. 1. Small quantities of certain elements may be found in alloy steel which are not specified or required. These elements are considered as incidental and acceptable to the following maximum amounts: copper to 0.35%, nickel to 0.25%, chromium to 0.
36、20%, and molybdenum to 0.06%. 2. Maximum sulfur content is 0.040% and maximum phosphorus content is 0.025%. 3. Ranges and limits are subject to the permissible variations for product analysis shown in SAE J409. 4. These steels can be expected to contain 0.0005 to 0.003% boron. SAE J1868 Revised FEB2
37、010 Page 5 of 28FIGURE 1 - COMPARISON OF H-BAND AND RH-BAND FOR SAE 4140 STEEL SAE J1868 Revised FEB2010 Page 6 of 28FIGURE 2 - LIMITS FOR HARDENABILITY BAND 15B21RH SAE J1868 Revised FEB2010 Page 7 of 28FIGURE 3 - LIMITS FOR HARDENABILITY BAND 15B35RH SAE J1868 Revised FEB2010 Page 8 of 28FIGURE 4
38、- LIMITS FOR HARDENABILITY BAND 3310 RH SAE J1868 Revised FEB2010 Page 9 of 28FIGURE 5 - LIMITS FOR HARDENABILITY BAND 4027 RH SAE J1868 Revised FEB2010 Page 10 of 28FIGURE 6 - LIMITS FOR HARDENABILITY BAND 4118 RH SAE J1868 Revised FEB2010 Page 11 of 28FIGURE 7 - LIMITS FOR HARDENABILITY BAND 4120
39、RH SAE J1868 Revised FEB2010 Page 12 of 28FIGURE 8 - LIMITS FOR HARDENABILITY BAND 4130 RH SAE J1868 Revised FEB2010 Page 13 of 28FIGURE 9 - LIMITS FOR HARDENABILITY BAND 4140 RH SAE J1868 Revised FEB2010 Page 14 of 28FIGURE 10 - LIMITS FOR HARDENABILITY BAND 4145 RH SAE J1868 Revised FEB2010 Page 1
40、5 of 28FIGURE 11 - LIMITS FOR HARDENABILITY BAND 4161 RH SAE J1868 Revised FEB2010 Page 16 of 28FIGURE 12 - LIMITS FOR HARDENABILITY BAND 4320 RH SAE J1868 Revised FEB2010 Page 17 of 28FIGURE 13 - LIMITS FOR HARDENABILITY BAND 4620 RH SAE J1868 Revised FEB2010 Page 18 of 28FIGURE 14 - LIMITS FOR HAR
41、DENABILITY BAND 4820 RH SAE J1868 Revised FEB2010 Page 19 of 28FIGURE 15 - LIMITS FOR HARDENABILITY BAND 50B40 RH SAE J1868 Revised FEB2010 Page 20 of 28FIGURE 16 - LIMITS FOR HARDENABILITY BAND 5130 RH SAE J1868 Revised FEB2010 Page 21 of 28FIGURE 17 - LIMITS FOR HARDENABILITY BAND 5140 RH SAE J186
42、8 Revised FEB2010 Page 22 of 28FIGURE 18 - LIMITS FOR HARDENABILITY BAND 5160 RH SAE J1868 Revised FEB2010 Page 23 of 28FIGURE 19 - LIMITS FOR HARDENABILITY BAND 8620 RH SAE J1868 Revised FEB2010 Page 24 of 28FIGURE 20 - LIMITS FOR HARDENABILITY BAND 8622 RH SAE J1868 Revised FEB2010 Page 25 of 28FI
43、GURE 21 - LIMITS FOR HARDENABILITY BAND 8720 RH SAE J1868 Revised FEB2010 Page 26 of 28FIGURE 22 - LIMITS FOR HARDENABILITY BAND 8822 RH SAE J1868 Revised FEB2010 Page 27 of 28FIGURE 23 - LIMITS FOR HARDENABILITY BAND 9310 RH SAE J1868 Revised FEB2010 Page 28 of 288. NOTES 8.1 Marginal Indicia A cha
44、nge bar (I) located in the left margin is for the convenience of the user in locating areas where technical revisions, not editorial changes, have been made to the previous issue of this document. An (R) symbol to the left of the document title indicates a complete revision of the document, including technical revisions. Change bars and (R) are not used in original publications, nor in documents that contain editorial changes only. PREPARED BY THE SAE CARBON AND ALLOY STEELS COMMITTEE
