1、MILITARY SPECIFICATION SUFFACE HARDENING: FLAME AND INDUCTION (FOR FERROUS ALLOYS) This specification is approved for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Scope. This specification covers the surface hardening of ferrous cpenching or relatively rpid cooling
2、operation (see 6.1 and 3.3 and 3.5). - I alloys by gas flame or electromagnetic induction heating followed by a 1.2 Classification. Surface hardening shall be classified according to the followirLg heating methods: Method I - Flame hardening Hethod II - Induction hardening 2. APPLICABLE DOCUMENTS 2.
3、 J. Government documents. 2.1.1 Specifications, standards, and handbooks. Unless otherwise specified, the following specifications, standards, and handbooks of the issue listed in that issue of the Department cf Defense Index of Specifications and Standards (CoDISS) specified in the solicitation for
4、m a part of this specification to the extent specified herein. SPECIFICATIONS MILITAIiY MIL-1-6868 - Inspection Process, Magnetic Particle 2 d Eeneficial ccmnents (reca.wendations, additions, deletions) an any pertinent ata which may De of use in improving this document should be addressed to: Direc
5、tor, US Army Materials and Mechanics Research Center, ATm: DRXMR-SMS, Watertown, &IA 02172 by using the self-addressed Standardization Document Improvement Proposal (GD Form 1426) appearing at the end of this dccument or by letter. i 140 DELIVERABLE CATA REQUIRED BY THIS DOCUMENT Provided by IHSNot
6、for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-S-12515C STANDARDS FEDERAL Fed. Test Method Std. No. 151 - Metalst Test Methods MILITARY MIL-STD-105 - Sampling Procedures and Tables for Inspection by Attributes (Copies of specifications, standards, handbooks, drawi
7、ngs, and publications required by manufacturers in connection with specific acquisition functions should be obtained from the contracting activity or as directed by the contracting officer.) 2.2 Other publications. The following document form a part of this specification to the extent specified here
8、in. The issues of the documents which are indicated as DoD adopted shall be the issue listed in the current DoDISS and the supplement thereto, if appliaable. AMERICAN SOCIETY FOR TESTING AND MATERIAfrS (ASTM) ASTM E 10 - Brinell Hardness of Metallic Materials, Testfor ASTM E 18 - Rockwell Hardness a
9、nd Rockwell Superficial Hardness of Metallic Materials, Tests for (Application for copies should be addressed to the American Society for Testing and Materials, 1916 Race Street, Philadelphia, Pennsylvania 19103.) 2.3 Order of precedence. In the event of a conflict between the text of this specifica
10、tion and the references cited herein, the text of this specification shall take precedence. 3 . REQUIREMENTS 3.1 Preproduction. Unless otherwise specified in the invitation for bids, contract or order, prior to the surface hardening of any parts, the contractor shall submit sample parts or approved.
11、contro1 specimens processed by the procedure to be used in production (see 6.2). A processing procedure for each individual part shall be prepare including the factors shown in table I for the applicable method of processing. The submitted procedures shall be considered acceptable if the sample part
12、s or control specimens meet all the requirements of the drawing and this specification. 3.2 Procedural changes. Unless otherwise specified by the procuring activity any major change in any one of the procedure factors listed in table I, without the approval of the procuring activity, shall require a
13、 resubmittal of sample parts reflecting the new processing procedure as well as a record of the new processing procedure. P zi . :* 3.3 Surface Preparation. Surfaces to be hardened shall be clean and free of any decarburization to assure proper response to the surface hardening operation. 2 Provided
14、 by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-S-12515C Table I. Procedure factors Factor Method I Method II a b C d e f g h i j k 1 KI n o Size, weight, shape of part Same Composition of material Same Conition, mechanical properties Same previous heat
15、treatment (see 3.3 ana 3.5) Required hardness range Required depth of hardness Method of supporging and holding or clamping part Method of moving part or flame Fuel gas used Pressures and regulator and gage settings Type (s) and size (6) of heating tiP(S) Flame characteristics and flame inner-cone-t
16、o-work distance Rate of travel of heating tip(s) or work Quenching method and medium Coolant temperature, volume, tem- pera ture control arrangement (if any) Gas (fuel) an oxygen consumption per part or per unit of surface treated Same Same Same Method of moving work or induction head (heating coil)
17、 Induction frequency (c.p.s of heating current) Energy requirement (k.v.a) Induction head (heating coil) design Distance between induction hea(s) and work (flux air gap) Rate of travel of work or i nduc t ion head ( 6) Same Same Energy (k. w. h) requirenent per part or per unit of surface treated 3
18、Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-S-12515C Factor Method I Method II P Heating time required per part surface hardened q Time between end of heating cycle and start of quenching cycle r Temperature and time of stress relieving Same
19、Same Same S Design of work Holding Fixture Same 3.4 Hardness. The parts shall meet the hardness requirements of the applicable drawing after the surface hardening operation. If hardness values are not specified, the minimum hardness number shall be, after tempering, (72HRA or 43HRC) . 3.4.1 Depth of
20、 hardeninq. The depth of hardening is the “effective case depth“. Unless otherwise specified, the hardness value to measure the effective case depth should be per.the following table: Table II . Material Carbon Content (%) Effective Case Depth Hardness (Rc) 0.28 to 0.32 35 0.33 to 0.42 40 0.43 to 0.
21、52 45 O .53 and over 50 3.4.2 Area of hardening. When only localized areas are to be hardened, the areas shall be so designated on the applicable drawing by dimensionally indicating the basic area to be hardened as well as the allowable overlap. 3.4.3 Core hardness. Core hardness shall be as specifi
22、ea on the applicable drawing. Areas that are not surface hardened shall have a surface hardness equal to the core hardness requirement. 3.5 Prior heat treatment. All parts shall be properly heat treated to the specified core hardness prior to surface hardening. 3.6 Stress relief. Stress relief shall
23、 be as specified on the applicable rawings or as authorized by the procuring activity. However, if no stress relief is specifed, all surface hardened parts shall, after hardening, be tempered at a minimum tempering temperature of 4000F. for at least one hour per each inch of part thickness. In order
24、 to avoid temper embrittlement, the contractor should exercise proper discretion in the selection of a tempering temperature for the steel involved. 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-S-12515C 3.7 Workmanship. 3.7.1 Surface defects
25、. Surface hardened parts shall be free of cracks, excessive scaling, blisters or other detrimental defects. Unless otherwise Specified in the contract or purchase order, preproduction sample parts shall be subject to ffiagnetic particle inspection for workmanship defects prior to approval of the sur
26、face hardening process. 3.7.2 Warpage. The surface hardening process shall cause no warpage or dimensional changes, not in conformance with the applicable drawings. Straightening or other corrective measures shall not be permitted unless approved by the procuring activity. 4. QUALITY ASSURANCE PROVI
27、SIONS 4.1 Responsibility for inspection. Unless otherwise specified in the contract or purchase order, the contractor is responsible for the performance of all inspection requirements as specifiea herein. Except as otherwise specified in the contract or purchase order, the contractor may use his own
28、 or any other facilities suitable for the performance of the inspection requirements specified herein, unless disapproved by the Government. The Government reserves the right to perform any of the inspections set forth in the specification where such inspections are deemed necessary to assure suppli
29、es and services conform to prescribed requirements. 4.2 Classification of inspection. The inspection requirements specified herein are classified as follows: 1. Preproduction inspection (see 4.3) . 2. Acceptance inspection (see 4.7). 4.3 Preproduction inspection. Preproduction inspection, except as
30、otherwise indicated- in this specification, shall utilize the same requirements an test methods as the production acceptance inspection. 4.4 Lot for acceptance inspection. A lot shall consist of all parts of the same drawing or part number, surface hardened by the same process, and presented for ins
31、pection at one time. 4.5 Sampling 4.5.1 Preproduction. The number of safiples shall be specified by the procuring activity (see 6.2). 4.5.2 Acceptance. 4.5.2.1 Hardness. Unless otherwise specified by the procuring activity, sarrpling for hardness shall be Level II, MIL-STD-105. The Acceptable Qualit
32、y Level (AGL) shall be 4.0 percent defective. 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-L MIL-S-LZSLSC NF H 7797706 OY205213 O -I MIL-S-12515C 4.5.2.2 Depth of hardening. Sampling for depth of hardening shall be as specifie by the procuring a
33、ctivity (see 6.2). 4.6 Examination. 4.6.1 Visual. The samples shall be examine6 in accordance with the sampling procedures specified by the procuring activity for compliance with the surface requirements of 3.7.1 (see 6.2). 4.6.2 Warpaqe. The samples selected for visual examination in 4.5.1 shall al
34、so be measure for Compliance with the warpage requirements of 3.7.2. 4.7 Tests. 4.7 . 1 Test specimens. 4.7.1.1. Hardness. Specimens shall be prepared in accordance with ASTM E 10 or E 18 as applicable. 4.7.1.2 Depth of hardening. The sample parts or control specimens shall be sectioned perpendicula
35、r to the hardened surface and the resulting cut face shall be metallographically polished. 4.7.2. ,Test procedure. 4.7.2.1 Hardness. Hardness tests shall be conucted in accordance with ASTM E 10 or E18 as applicable. 4.7.2.2 Depth of hardening. Depth of hardness shall be determined by etching the po
36、lished face- and measuring by conducting a hardness traverse through the hardened zone perpendicular to the surface. 4.7.2.3 Magnetic particle inspection. Unless otherwise specified in the contract or purchase order, magnetic particle inspection in accordance with MIL-1-6868 shall be use to check pr
37、eproduction samples for surface defects. 4.0 Rejection and retests. 4.8.1 Preproduction. The failure of preproduction samples to comply with any of the requirements of this specification shall be cause for rejection of the surface hardening process. Retesting shall not be conducted until it is shown
38、, to the satisfaction of the procuring activity, that the process procedure has been corrected. 4.8.2 Acceptance. Unless otherwise specified in the contract or order, rejection and retest shall be conducted in accordance with the general section of Fed. Test Method Std. No. 151 (see 6.2). 6 Provided
39、 by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Custodian: Amy - MR Navy - SH Air Force - 20 Review Activities: Amy - AT, AR KtL-S-12515C 5. PACKAGING 5.1 Packaging requirements. Not applicable 6. NOTES 6.1 Intended use. The procedures covered in this specif
40、ication are intended for use in surface hardening ferrous parts, such as, shafts, pinions, worms, hearing components , spur or bevel gears, etc. 6.2 Ordering data. Procurement documents should specify the following: (at Title, number and date of this specification (b) Method of surface hardening, if
41、 only one method is allowable (see 1.2). (c) Nunker and destination of preproduction samples, if required (see 3.1 and 4.5.1). (d) Number of acceptance samples (see 4.5.2.1, 4.5.2.2, and 4.6.1). Preparing activity: Army - MR Project No. MFFP-0211 User activities: Amy - MI (WP# ID-0531AJDISK 0117A. FOP A”PC USE ONLY) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
