1、BRITISH STANDARD AEROSPACE SERIES CONFIRMED AUGUST 1985 BS 2S 142:1977 (Superseding BSS142) Incorporating Amendment No. 1 Specification for 1 % chromium- molybdenum steel billets, bars, forgings and parts (900 1100 MPa: limiting ruling section40 mm) UDC 629.7:669.152628 4BS2S 142:1977 This British S
2、tandard, having been prepared under the directionof the Aerospace Standards Committee, was published under the authority ofthe Executive Board on 29 April 1977 BSI 01-2000 The following BSI references relate to the work on this standard: Committee reference ACE/15 Draft for comment 75/76712DC ISBN 0
3、 580 09592 4 A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This docume
4、nt comprises a front cover, an inside front cover, pages i and ii, pages 1 and 2 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publicatio
5、n Amd. No. Date of issue Comments 3528 August 1981 Indicated by a sideline in the marginBS2S 142:1977 BSI 01-2000 i Contents Page 1 Inspection and testing procedure 1 2 Manufacture 1 3 Chemical composition 1 4 Surface dressing 1 5 Condition 1 6 Heat treatment 2 7 Mechanical properties 2ii blankBS2S
6、142:1977 BSI 01-2000 1 NOTE 1The requirements for steel bars of this chemical composition for the manufacture of forged bolts and forged nuts are given inBSS158. NOTE 2The specified chemical composition complies with AECMA Recommendation FE-PL43S. 1 Inspection and testing procedure 1.1 General. This
7、 British Standard shall be used in conjunction with the relevant sections of the latest issue ofBSS100 as follows: 1.2 Sulphur printing or deep etching tests. One sample shall be taken from each ingot for sulphur printing or deep etching tests. 2 Manufacture The material shall be manufactured by an
8、electric process. 3 Chemical composition The steel shall contain: 4 Surface dressing The material shall be overall dressed. 5 Condition 5.1 Unless otherwise required by the order, the material shall be supplied in the appropriate condition stated below. 5.2 Parts shall be supplied finally heat treat
9、ed. Bars for machining delivered in other than the finally heat treated condition (see5.1) sections 1 and 2 Bars for machining delivered in the finally heat treated condition sections 1 and 3 Forging stock and billets and bars for subsequent working sections 1 and 5 Forgings sections 1 and 6 Parts f
10、inally heat treated after machining sections 1 and 7 Element % min. max. Carbon 0.22 0.29 Silicon 0.15 0.35 Manganese 0.50 0.80 Phosphorus 0.020 Sulphur 0.015 Chromium 0.9 1.2 Molybdenum 0.15 0.25 Nickel 0.30 Designation Form Condition of supply S142B Black bars for machining Finally heat treated S1
11、42D Bright bars for machining Finally heat treated before or after cold drawing or cold rolling or machining or grinding S142A Forging stock and billets and bars for subsequent working Softened S142C Forgings Finally heat treatedBS2S 142:1977 2 BSI 01-2000 6 Heat treatment 6.1 Softening treatment. T
12、he softening treatment shall consist of heating uniformly at a temperature of not less than650 C. 6.2 Final heat treatment 6.2.1 The final heat treatment shall consist of the following: a) Hardening. Heat uniformly at a temperature between830 C and880 C, followed by cooling in oil or water. b) Tempe
13、ring. Heat uniformly at a temperature of not less than520 C, followed by cooling in air. 6.2.2 Hardened and tempered bars which have been subjected to a cold straightening or cold rolling operation shall be given a stress-relieving treatment which shall be sufficient to restore the proof stress. 7 M
14、echanical properties 7.1 Tensile test at room temperature and impact test. The mechanical properties obtained from test pieces shall be as follows. NOTEInformation on SI units is given inBS3763 ”The International System of units (SI)” andBS350 “Conversion factors and tables”. 7.2 Hardness test 7.2.1
15、 The hardness of material heat treated in accordance with 6.1 shall be not greater than212HB. 7.2.2 The hardness of material, parts and test samples heat treated in accordance with 6.2 shall be: 269 min./331 max. HB or 285 min./350 max. HV. 0.2 % proof stress Tensile strength Elongation Izod impact
16、min. min. max. min. min. MPa (= N/mm 2 ) MPa (= N/mm 2 ) MPa (= N/mm 2 ) % ft lbf 700 900 1 100 12 30blankBS 2S 142:1977 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the UK view on
17、 standards in Europe and at the international level. It is incorporated by Royal Charter. Revisions BritishStandards are updated by amendment or revision. Users of BritishStandards should make sure that they possess the latest amendments or editions. It is the constant aim of BSI to improve the qual
18、ity of our products and services. We would be grateful if anyone finding an inaccuracy or ambiguity while using this BritishStandard would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover. Tel:02089969000. Fax:02089967400. BSI
19、offers members an individual updating service called PLUS which ensures that subscribers automatically receive the latest editions of standards. Buying standards Orders for all BSI, international and foreign standards publications should be addressed to Customer Services. Tel:02089969001. Fax:020899
20、67001. In response to orders for international standards, it is BSI policy to supply the BSI implementation of those that have been published as BritishStandards, unless otherwise requested. Information on standards BSI provides a wide range of information on national, European and international sta
21、ndards through its Library and its Technical Help to Exporters Service. Various BSI electronic information services are also available which give details on all its products and services. Contact the Information Centre. Tel:02089967111. Fax:02089967048. Subscribing members of BSI are kept up to date
22、 with standards developments and receive substantial discounts on the purchase price of standards. For details of these and other benefits contact Membership Administration. Tel:02089967002. Fax:02089967001. Copyright Copyright subsists in all BSI publications. BSI also holds the copyright, in the U
23、K, of the publications of the international standardization bodies. Except as permitted under the Copyright, Designs and Patents Act 1988 no extract may be reproduced, stored in a retrieval system or transmitted in any form or by any means electronic, photocopying, recording or otherwise without pri
24、or written permission from BSI. This does not preclude the free use, in the course of implementing the standard, of necessary details such as symbols, and size, type or grade designations. If these details are to be used for any other purpose than implementation then the prior written permission of BSI must be obtained. If permission is granted, the terms may include royalty payments or a licensing agreement. Details and advice can be obtained from the Copyright Manager. Tel:02089967070.
