AMS H-6875A美国的军用热处理标准

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 therefrom, 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. All rights reserved. Printed in U.S.A. QUESTIONS REGARDING THIS DOCUMENT: (724) 772-7161 FAX: (724) 776-0243 TO PLACE A DOCUMENT ORDER: (724) 776-4970 FAX: (724) 776-0790 SAE WEB ADDRESS: http://www.sae.org 400 Commonwealth Drive, Warrendale, PA 15096-0001 AEROSPACE MATERIAL SPECIFICATION Submitted for recognition as an American National Standard AMS-H-6875A Issued NOV 1998 Revised DEC 1998 Heat Treatment of Steel Raw Materials NOTICE This document has been taken directly from U.S. Military Specification MIL-H-6875H, Amendment 2 and contains only minor editorial and format changes required to bring it into conformance with the publishing requirements of SAE technical standards. The initial release of this document is intended to replace MIL-H-6875H, Amendment 2. Any part numbers established by the original specification remain unchanged. The original Military Specification was adopted as an SAE standard under the provisions of the SAE Technical Standards Board (TSB) Rules and Regulations (TSB 001) pertaining to accelerated adoption of government specifications and standards. TSB rules provide for (a) the publication of portions of unrevised government specifications and standards without consensus voting at the SAE Committee level, and (b) the use of the existing government specification or standard format. Under Department of Defense policies and procedures, any qualification requirements and associated qualified products lists are mandatory for DOD contracts. Any requirement relating to qualified products lists (QPL’s) has not been adopted by SAE and is not part of this technical report. 1. SCOPE: 1.1 Scope: This specification covers the requirements for heat-treatment of four classes of steel (see 1.2) and the requirements for furnace equipment, test procedures and information for heat-treating procedures, heat-treating temperatures and material (see 6.11) test procedures. This specification is applicable only to the heat treatment of raw material (see 6.1.1); it does not cover the requirements for the heat treatment of steel parts (see 3.4 and 6.1.2). This specification also describes procedures which, when followed, will produce the desired properties and material qualities within the limitations of the respective alloys tabulated in Tables IA, IB, IC and ID. Alloys other than those specifically covered herein may be heat treated using all applicable requirements of this specification. Copyright © 2006 SAE International Reaffirmed APR 2006 Copyright SAE International Provided by IHS under license with SAE Licensee=Messier Dowty/5905381001 Not for Resale, 09/06/2006 02:26:35 MDTNo reproduction or networking permitted without license from IHS - - ` ` ` , , ` ` , ` ` ` , , , , , ` , ` , ` ` ` , , ` , - ` - ` , , ` , , ` , ` , , ` - - - AMS-H-6875A SAE AMS-H-6875A - 2 - 1.1.1 Limitations: Unless otherwise specified, this specification is not applicable to heating or to intermediate (non-final) heat treatment, of raw material, e.g. for hot working. Processes not covered include deliberate surface heat-treating and specialized heat-treating, such as induction hardening, flame hardening, carburizing, nitriding; however, this specification may be referenced for equipment and controls. Austempering, ausbay quenching and martempering may be used when specified by the cognizant engineering organization. 1.2 Classification: Steels covered by this specification are classified into the following four classes. Unless otherwise specified, the process and equipment requirements in this specification refer to all classes of steel tabulated in Tables IA, IB, IC and ID, respectively. Class A - Carbon and low alloy steel Class B - Martensitic corrosion-resistant steel Class C - Austenitic corrosion-resistant steel Class D - Precipitation-hardening and maraging steel 2. APPLICABLE DOCUMENTS: The following publications, of the issues in effect on date of invitation for bids or request for proposal, form a part of this specification to the extent specified herein. 2.1 SAE Publications: Available from SAE, 400 Commonweath Drive, Warrendale, PA 15096-0001. AMS 2418 Copper Plating AMS 2424 Nickel Plating, Low Stressed Deposit AMS 2750 Pyrometry AMS 2759 Heat Treatment of Steel Parts, General Requirements AMS 2759/3 Heat Treatment of Precipitation Hardening Corrosion Resistant and Maraging Steel Parts 2.2 ASTM Publications: Available from ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959. ASTM A 262 Detecting Susceptibility to Intergranular Attack in Austenitic Stainless Steels ASTM A 370 Mechanical Testing of Steel Products, Methods and Definitions for ASTM C 848 Young’s Modulus, Shear Modulus, and Poisson’s Ratio for Ceramic Whitewares by Resonance, Test Method for ASTM D 3520 Test Method for Quenching Time of Heat Treating Fluids (Magnetic Quenchometer Test) ASTM E 3 Metallographic Specimens, Preparation of ASTM E 8 Tension Testing of Metallic Materials Copyright SAE International Provided by IHS under license with SAE Licensee=Messier Dowty/5905381001 Not for Resale, 09/06/2006 02:26:35 MDTNo reproduction or networking permitted without license from IHS - - ` ` ` , , ` ` , ` ` ` , , , , , ` , ` , ` ` ` , , ` , - ` - ` , , ` , , ` , ` , , ` - - - AMS-H-6875A SAE AMS-H-6875A - 3 - 2.2 (Continued): ASTM E 10 Brinell Hardness of Metallic Materials ASTM E 18 Rockwell Hardness and Rockwell Superficial Hardness of Metallic Materials ASTM E 384 Microhardness of Materials 2.3 U.S. Government Publications: Available from DODSSP, Subscription Services Desk, Building 4D, 700 Robbins Avenue, Philadelphia, PA 19111-5094. QQ-N-290 Nickel Plating (Electroplated) MIL-C-14550 Copper Plating, (Electrodeposited) 3. REQUIREMENTS: 3.1 Equipment: 3.1.1 Furnace media and protective coatings: 3.1.1.1 Atmosphere for Classes A, B, C and D steel parts: The gaseous medium for heat treating Classes A, B, C and D steel parts above 1250 °F shall be air/products of combustion, argon, helium, hydrogen, nitrogen, or blends of these gases, vacuum, exothermic, endothermic, nitrogen based, or dissociated ammonia conforming to the requirements below. Supplementary protective coatings, in accordance with 3.3.1.3, may be used where necessary. Atmosphere Class A 1/ Class B 1/ Class C 1/ Class D 1/ Air/Products of Combustion X 2/ X 2/ X X Argon 3/ X X X X Helium 3/ X X X X Hydrogen 3/ X X 7/ X X 5/ Nitrogen 3/ 6/ X 8/ X X X10/ Vacuum X X X X11/ Exothermic 4/ X X X No Nitrogen based or endothermic 4/ X 8/ X No No Dissociated Ammonia 3/ 9/ No No X No 1/ X - Denotes atmosphere acceptable for use on that designated class of steel with or without limitations. Copyright SAE International Provided by IHS under license with SAE Licensee=Messier Dowty/5905381001 Not for Resale, 09/06/2006 02:26:35 MDTNo reproduction or networking permitted without license from IHS - - ` ` ` , , ` ` , ` ` ` , , , , , ` , ` , ` ` ` , , ` , - ` - ` , , ` , , ` , ` , , ` - - - AMS-H-6875A SAE AMS-H-6875A - 4 - 2/ Unless otherwise specified, an air/product of combustion atmosphere shall be limited to precipitation hardening, tempering, stress relieving and 1400 °F transformation treatments. An air/product of combustion atmosphere may be used for treatment above 1400 °F for Classes A and B material which will have a minimum of 0.020 inch metal removed from all surfaces after heat treatment or which have been protected by electroplates. 3/ Dew point shall be not higher than -40 °F at the exit of the working zone. 4/ Atmosphere shall be refined or blended to avoid a change in carbon content at the surface of the material as specified in 3.3.3. A product of combustion at -40 °F maximum dew point (e.g. endothermic) may be used for class A material which allows 0.003 inch maximum partial decarburization at the surface. Exothermic atmosphere permissible only for heat treatment of class A mill products. 5/ Acceptable up to 1950 °F. 6/ Nitrogen atmosphere does not include nitrogen from dissociated ammonia 7/ Only acceptable when tempered at 1000 °F or above. Acceptable for annealing. 8/ Class A steels may be fine grain copper plated 0.002 to 0.005 inch thick in accordance with MIL-C-14550 or AMS 2418 or nickel plated per AMS 2424 or QQ-N-290 or equivalent as a supplementary surface protection. Other supplementary protective coatings may be used if approved by the cognizant engineering organization. 9/ Permissible only for annealing of mill products providing residual ammonia at the outlet of the generator does not exceed 15 ppm. 10/ The use of a nitrogen atmosphere shall be limited to heat treating temperatures of 1400 °F and below. A nitrogen atmosphere may be used for heat treatment above 1400 °F provided a minimum of 0.020 inches of metal is subsequently removed from all surfaces of heat treated material. 11/ Nitrogen is not permitted as a partial pressure above 1400 °F. Nitrogen may be used as a backfill quench for vacuum heat treatments performed at or below 1925 °F. Copyright SAE International Provided by IHS under license with SAE Licensee=Messier Dowty/5905381001 Not for Resale, 09/06/2006 02:26:35 MDTNo reproduction or networking permitted without license from IHS - - ` ` ` , , ` ` , ` ` ` , , , , , ` , ` , ` ` ` , , ` , - ` - ` , , ` , , ` , ` , , ` - - - AMS-H-6875A SAE AMS-H-6875A - 5 - 3.1.1.2 Atmospheres for mill products: Furnaces for mill products shall be supplied with gases of a consistent analysis such that the product meets the requirements of the appropriate material specification. Furnaces, gases, and gas generators shall be controlled. Ducts and working zones shall be sealed to prevent contamination by outside gases. Vacuum furnaces shall have a calibrated recording instrument for sensing the vacuum in the vacuum chamber. All atmosphere furnaces and gas supply lines shall be purged with the designated and approved atmosphere gas for the specific steel to be heat treated. 3.1.1.3 Salt baths: Salt baths may be used for the heat treatment of Classes A and B steels. Salt baths shall be tested initially and at least once each week and shall be adjusted to assure that part surfaces shall be free from general corrosion, carburization and decarburization or intergranular attack in excess of limits specified in 3.3.3. Additives used for adjustments shall be limited to salts in bath and rectifiers recommended by the salt manufacturer. 3.1.1.4 Temperature uniformity: The design and construction of heating equipment shall be such that the temperature at any point in the furnace working zone or work load shall comply with AMS 2750. 3.1.1.5 Temperature range and set temperature: The set temperature on the furnace control instrument shall be such that the load temperature falls within the specified range, taking into account the temperature uniformity of the furnace. In continuous furnaces used to anneal and normalize mill products, a thermal head may be used. The temperature of the mill product shall not exceed the maximum processing temperature. 3.1.2 Pyrometry and furnace temperature control: The requirements and procedures for control and testing of furnaces, ovens, salt baths, vacuum furnaces, refrigeration equipment and allied pyrometric equipment used for heat treatment shall be in accordance with AMS 2750 and the appendix thereto (see 4.2.1 and 4.2.2). Equipment which cannot be controlled and tested in accordance with AMS 2750 shall be controlled and tested as directed by the cognizant engineering organization. 3.1.3 Quenching equipment: 3.1.3.1 Quench baths: Quench baths shall permit complete immersion of material, provide for adequate circulation of the media or agitation of material, provide a means for indicating the temperature of the media and for cooling and heating, as applicable. Baths shall be adequate to produce the required properties in the most massive material to be quenched. 3.1.3.1.1 Oil-quenching baths: The oil-quenching medium shall be between 60 °F and 160 °F at the beginning of the quenching operation and shall not exceed 200 °F at any time during the quenching operation, unless otherwise approved by the cognizant engineering organization. The temperature of the oil quenching media shall not exceed the manufacturers recommended operating range. Quench oil used in integral quench vacuum furnace systems, where the quench chamber is below atmospheric pressure, shall be vacuum degassed at approximately the maximum recommended temperature for the quenchant initially and after each major addition of oil. Copyright SAE International Provided by IHS under license with SAE Licensee=Messier Dowty/5905381001 Not for Resale, 09/06/2006 02:26:35 MDTNo reproduction or networking permitted without license from IHS --```,,``,```,,,,,`,`,```,,`,-`-`,,`,,`,`,,`--- AMS-H-6875A SAE AMS-H-6875A - 6 - 3.1.3.1.2 Aqueous polymer quenchants: Aqueous polymer quenchants may be used as permitted in Tables IA through ID. The temperature of the aqueous polymer quenchant baths shall not exceed the manufacturers recommended operating range. These baths shall also be adequately circulated to assure homogeneity of the aqueous polymer quenchant media. 3.1.3.1.3 Quenching from salt bath furnaces: Water-quenching baths employed in cooling steel parts which have been heated in salt-bath furnaces should be provided with an inflow of fresh water to prevent a concentration of dissolved salts in the tanks. Polymer quenching baths when used in conjunction with salt bath furnaces shall be monitored weekly so that the salt content of the bath shall not exceed 6% by weight of the bath. All salt residues shall be removed from parts processed in salt-bath furnaces or quenched in brine, during or immediately following quenching. 3.1.3.1.4 Alternative Quenchants: In lieu of the stated methods in Tables IA through ID, steam, air, water sprays, inert gases, polymers, molten salts or other commercial quenching media or processes may be used when approved by the cognizant engineering organization, providing equivalence with respect to mechanical properties and corrosion resistance, as applicable to the material and its application, can be substantiated. Equivalence tests shall be as specified by the cognizant engineering organization. Where air quenching is permitted in the Tables IA-ID, argon and helium may be used; other inert gases may be substituted when approved by the cognizant engineering organization. 3.1.3.2 Location of quenching equipment: Quenching equipment shall be located in such a manner and handling facilities shall function with sufficient speed to prevent the initiation of transformation or sensitization prior to quenching. 3.1.4 Miscellaneous equipment: Suitable jigs, fixtures, trays, hangers, racks, ventilators, and so on, shall be employed as necessary for the proper handling of the work and for maintenance of the major items of equipment. The use of heat-treating fixtures or fixture materials where the contact with or proximity to the material could contaminate the material or reduce the heating, cooling or quenching rates to less than required for complete transformation or through-hardening of the material shall not be permitted. 3.1.5 Cleaning Equipment: Equipment shall be provided to clean material in accordance with 3.3.1.1. Where toxic or harmful cleaners are employed, they shall be used in compliance with the applicable health and safety regulations. 3.2 Thermal treatment: Copyright SAE International Provided by IHS under license with SAE Licensee=Messier Dowty/5905381001 Not for Resale, 09/06/2006 02:26:35 MDTNo reproduction or networking permitted without license from IHS - - ` ` ` , , ` ` , ` ` ` , , , , , ` , ` , ` ` ` , , ` , - ` - ` , , ` , , ` , ` , , ` - - - AMS-H-6875A SAE AMS-H-6875A - 7 - 3.2.1 Rate of heating: Heating rates shall be controlled to prevent damage to the material (see 6.2). Pre- heating at 1000 °F-1200 °F is recommended before heating material above 1300 °F if the material: (a) Has been previously hardened above Rc 35, or is made of steel of 0.50 (nominal) percent carbon or over, or (b) Has abrupt changes of section, or sharp re-entrant angles, or (c) Has been finish machined. 3.2.2 Hardening of Classes A and B material: Classes A and B material shall be hardened by austenitizing, quenching and tempering. 3.2.2.1 Prior condition of Class A steel parts: 3.2.2.1.1 H-11 material: H-11 parts shall be in the annealed condition, prior to hardening, unless it has been hot headed. Hot headed H-11 material shall be annealed, prior to hardening, by furnace cooling from 1625 °F ± 25 °F to at least 1000 °F, at a maximum rate of 50 °F per hour. 3.2.2.1.2 52100 or 1095 material: Parts made of 52100 or 1095 steel should be hardened from the spheroidize annealed condition. 3.2.2.1.3 Other Class A parts: Parts made from other Class A steels to be hardened and tempered to 220 ksi and above shall be either normalized, normalized and tempered, or normalized and sub-critical annealed, prior to initial austenitizing. Parts that have been welded shall be normalized, prior to hardening. Parts identified as damage tolerant, maintenance critical or fracture critical shall be normalized, normalized and tempered or normalized and subcritical annealed, regardless of the strength to which they are subsequently to be heat-treated. 3.2.2.2 Austenitizing: The austenitizing temperature shall conform to Tables IA and IB, as applicable. Parts shall be held within the specified temperature range for sufficient time for the necessary transformation and diffusion to take place. The recommended holding times at temperature are listed in Table IIA. 3.2.2.3 Quenching: Material shall be quenched from the austenitizing temperature in the quenchant specified in Tables IA or IB, as applicable. Material shall be cooled to or below the quenchant temperature before tempering. Material should be tempered within two hours after quench or within two hours after reaching room temperature after cold treatment. If hardened parts cannot be tempered within 2 hrs. of quenching, they can be snap tempered for one hour at 400 °F ± 25 °F or as appropriate to prevent cracking. Mill products shall be quenched in a manner consistent with commercial practice where Tables IA & IB are not applicable. They shall be cooled sufficiently and tempered within a period of time adequate to prevent quench cracking or conditions deleterious to end product mechanical properties and corrosion resistance. 3.2.2.4 Tempering: Material shall be tempered in accordance with Table III. When multiple tempering is used, material shall be cooled to room temperature between tempering treatments. The tempering temperatures listed in Tables IA or IB are recommended, unless indicated as mandatory by the footnotes. Copyright SAE International Provided by IHS under license with SAE Licensee=Messier Dowty/5905381001 Not for Resale, 09/06/2006 02:26:35 MDTNo reproduction or networking permitted without license from IHS --```,,``,```,,,,,`,`,```,,`,-`-`,,`,,`,`,,`--- AMS-H-6875A SAE AMS-H-6875A - 8 - 3.2.3 Hardening Class D steel: Class D steel parts shall be hardened by precipitation he