1、min. o .22 O .3 0.3 -_ - 2.5 O .4 -. - - - max. 0.32 0.75 O .8 O .O2 5 0.025 3.5 O .4 0.7 O .4 0.03 0.02 -,-_ I i BSI HC*7 74 ill lbZ4bb9 0099334 5 W j HC7:May:1974 (Superseding, in part, Ministry of efence specifications DTD 666 and DTD 51721 UDC 629.7 : 669.152628-14 e British Standard: Aerospace
2、Series Specification for 3% c h romiu m-molybden u m steel castings (880 - 1080 MPa) 1. Special foundry approval Manufacture of castings to this specification may be restricted to foundries specially approied in accordance with the requirements of British Standard HC 100, Section 1. e 2. Inspection
3、and testing procedure shall be used in conjunction with the relevant sections of;the latest iGoFBritish Standard I This British Standard HC 100 as follows: Re-melting stock Sections 1 and2 Precision castings Sections 1 and 3 i Sand castings Sections 1 and 4 I Centrifugai castings Sections 1 and 5 I
4、3. Chemical composition The remelting stock and the castings shall contain: _ A Element Carbon Silicon Manganese Phosphorus Sulphur Chromium Copper Molybdenuni Nickel Tin Vanadiuni - e 4. Condition Castings shall be supplied finally heat treated. Gr 1 British Standards Institution 9 2 Park Street Lo
5、ndon WIA 2BS Telephone O1 -629 9000 Telex 266933 O , I I 1 ES1 HC*7 74 I Lb24bb9 0099320 L Ui -_ - 700 i %80 1080 8 HC7:1974 30 30 5. Heat treatment Thc final !ie;it trcatmetit shall be as follows. S.1 Aiiiicaliiig. Heat unifornily at a temperature between 880 OC and 950 “C. 5.2 Hardening. Heat unif
6、ormly at a temperature between 880 “C and 920 OC and quench in oil. 5.3 Tempering. Heat uniformly at a temperature between 560 “C and 660 “C. 6. Mechanical properties 6.1 Tensile and impact. The tensile and impact properties obtained from test pieces representing castings, selected, prcparcd atid te
7、sted in accordance with the relevant requirements of British Standard HC 100, shall be: - 0.2 Q proof stws min. MPa .- - I ft lbf NOT1. 1iifc.niiaticin on SI units is given in BS 3763, The International System of units (SI), and BS 350, Conversion factors and txbles. 6.2 Bsrdiiess. The hardness of h
8、ardened and tempered castings and their representative test samples shall be: HRC 1TRectification Ofdm1 7.1 Correction of distortion. When permitted in accordance with British Standard HC 100, distortion shall be corrected after annealing and castings shall subsequently be hardened and tempered. 7.2
9、 Repair of castings by welding, When repair by welding is permitted in accordance with British Standard HC 100, this shall be carried out after annealing and castings shall subsequently : I - be hardened and tempered. r his Hritih Stmdsrd, having been approved by the Aerospace Industry Standards Com
10、mittee, was published under the authority of the Ilxt.ciilive Board cin 10 May, 1974. 0 l)ritih Stmdsrds Institution, 1974 ISW: 0 5x0 08372 1 Copyright I:w of Irit5.11 Standards are reminded that copyright subsists in all BSI publications. No part of this publication may be rqiriidiiccct in any form
11、 without the prior permission in writing of BSI. This does not precludc the free use, in the course of iiiiplcnientin the standard, of necessary details such as symbols and size, type or grade designations. Enquiries should be sddrcsietj to thc HSI Secretariat. Contract reqairements Attcrition i.: c
12、lrawri to thc hct that this British Standard does not purport to include all the necessary provisions of a contract. Revision of British Standards llrirish St:ind;ird :ire revised, when necessary, by the issue either of amendment slips or of revised editions. It is important that MCIS of Rritish Sta
13、ndards should ascertain that they are in possessbn of the latest amendments or editions. I iic fdlwiii: BSI rcfernccs relate to the work on this standard: (imimittcc rcicrencc ACE/60 Draft for comment 72/35126 DC Amendment No. 1 published and effective from 31 May 1982 to British Standard HC 7 : 197
14、4 (Aerospace Series) 3 % chromium-molybdenum steel castings (880-1080 MPa) AMD 3850 Revised text AMD 3850 May 1982 Clause 2. Inspectisti and testing procedure in line 1, after of insert the latest issue of. AMD 3850 May 1982 New clause 7 Insert the following new clause: 7. Rectification of defects 7
15、1 Correction of distortion. When permitted in accordance with British Standard HC 100, distortion shall be corrected after annealing and castings shall subsequently be hardened and tempered, 7.2 Repair of castings by welding. When repair by welding is permitted in accordance with British Standard HC 100, this shall be carried out after annealing and castings shali subsequently be hardened and tempered. 8205-0-1.4 k-B ACEIGQ
