1、BRITISH STANDARD AEROSPACE SERIES BS 7S 80:2002 Superseding BS 6S 80:1990 Incorporating Corrigendum No.1 High chromium-nickel corrosion resisting steel forging stock, bars, forgings and parts (880 to 1 080 MPa: limiting ruling section 100 mm) ICS 49.025.10 BS 7S 80:2002 This British Standard, having
2、 been prepared under the direction of the Engineering Sector Policy and Strategy Committee, was published under the authority of the Standards Sector Policy and Strategy Committee on 28 June 2002 BSI 5 March 2004 The following BSI references relate to work on this British Standard: Committee referen
3、ce ACE/15 Draft for comment 00/709810 DC ISBN 0 580 39836 6 Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Committee ACE/15, Wrought and cast steels for aerospace, upon which the following bodies were represented: Cast Metals Fede
4、ration (CMF) Civil Aviation Authority Airworthiness Confederation of British Metalforming Institute of Spring Technology Ministry of Defence UK Defence Standardization Society of British Aerospace Companies Ltd. UK Steel Association Co-opted members Amendments issued since publication Amd. No. Date
5、Comments 14978 Corrigendum No.1 5 March 2004 Changes to line 9 and line 20 of Table 2BS 7S 80:2002 BSI 5 March 2004 i Contents Page Committees responsible Inside front cover Foreword ii 1S c o p e 1 2 Normative reference 1 3 Technical requirements 1 Annex A (informative) 4 Bibliography 5 Table 1 Tec
6、hnical requirements for high chromium-nickel corrosion resisting steel forging stock and forgings 2 Table 2 Technical requirements for high chromium-nickel corrosion resisting steel bars, D ek 100 mm 3BS 7S 80:2002 ii BSI 5 March 2004 Foreword This British Standard has been prepared by Technical Com
7、mittee ACE/15. It is a new edition of BS 6S 80:1990, which is withdrawn. This new edition of BS 6S 80:1990 incorporates technical changes only. It does not reflect a full review or revision of the standard, which will be undertaken in due course. The following changes have been embodied in this issu
8、e of the standard. Permitted bundle mass during heat treatment has been removed in order to minimize the risk of ineffective quenching which is known to lead to temper embrittlement. Some guidance concerning the avoidance of temper embrittlement is provided in informative Annex A, to which the users
9、 attention is drawn. The units given in line 20 of the tables for impact strength are foot-pound-force (ft lbf) because Izod testing machines are calibrated in imperial units. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its corre
10、ct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 5 and a back cover. The BSI copyright notice displayed in this document indicates wh
11、en the document was last issued.BS 7S 80:2002 BSI 5 March 2004 1 1 Scope This British Standard specifies the characteristics of a high chromium-nickel corrosion resisting steel, supplied in the following forms, and as parts, for aerospace applications. a) Forging stock: softened, designation S 80A.
12、b) Forgings: D e100 mm, hardened and tempered, designation S 80C. c) Bar: softened, designation S 80E. d) Black bars: D e100 mm, hardened and tempered, designation S 80B. e) Bright bars: D e100 mm, hardened and tempered, designation S 80D. 2 Normative reference The following referenced document is i
13、ndispensable for the application of this document. For undated references, the latest edition of the publication referred to applies. BS 5S 100:1993, Procedure for inspection, testing and acceptance of wrought steels (other than plate, sheet, strip and tube). 1) 3 Technical requirements 3.1 The tech
14、nical requirements for material to this standard shall conform to those specified in Table 1 and Table 2, according to form. All material supplied shall conform to the requirements appropriate to its condition and dimensions as specified in the standard given in line 5 of the tables. NOTE Symbols an
15、d units are in accordance with prEN 4500-1, prEN 4500-5, BS 5555 and BS 5775-0. The format of the tables are derived from European Standards prEN 4500-1 and prEN 4500-5, although the presentation is slightly modified to make it more compatible with existing British Standards. 3.2 One sample shall be
16、 taken from each ingot for sulfur printing and deep etching tests. 3.3 The material shall be overall dressed at a suitable stage in manufacture. 3.4 Parts finally heat-treated after machining shall conform to the latest edition of BS S 100, Sections 1 and 7. 3.5 Parts shall be supplied in the fully
17、heat-treated condition. 1) The latest edition of this standard should be used. BS 5S 100:1993 is the latest edition at the time of publication.BS 7S 80:2002 2 BSI 5 March 2004 Table 1 Technical requirements for high chromium-nickel corrosion resisting steel forging stock and forgings 1 Material desi
18、gnation BS S 80 2 Chemical Element C Si Mn P S Cr Mo Ni Co Cu Nb Sn Ti V W Fe C o m p o s i t i o n m i n .0 . 1 21 5 . 02 . 0 Base % max. 0.20 1.0 1.0 0.030 0.025 18.0 0.30 3.0 0.05 0.30 0.05 0.02 0.05 0.20 0.05 3 Method of melting Air melted by an electric process 4.1 Form Forging stock Forgings 4
19、.2 Method of production Cast or wrought 4.3 Limit dimensions mm D ek 100 5.1 Technical specification BS S 100, Sections 1 and 5 BS S 100, Sections 1 and 6 6.1 Delivery condition Softened Hardened and tempered Heat treatment 650 C k a 1 000 C k k 1 020 C/OQ a640 C k k 660 C/OQ or WQ a620 C k k 640 C/
20、OQ or WQ a 7 Use condition Delivery condition Delivery condition Heat treatment Characteristics 8.1 Test sample Condition of supply Machined or forged test sample BS S 100, Section 5 BS S 100, Section 6 8.2 Test piece BS S 100, Section 5 BS S 100, Section 6 8.3 Heat treatment See line 29 Delivery co
21、ndition 9 Dimensions concerned mm D ek 63 63 D ek 100 D ek 63 63 D ek 100 11 Direction of test piece L L L L 12 T Temperature CA m b i e n t 13 Proof stress R p0,2 MPa U690 U690 U690 U690 14 Strength R m MPa 880 k R mk 1 080 880 k R mk 1 080 880 k R mk 1 080 880 k R mk 1 080 15 Elongation A % U12 U1
22、2 U12 U12 16 Reduction of area Z % 17 Hardness k277 HV 255 k HB k 321 255 k HB k 321 255 k HB k 321 255 k HB k 321 or 270 k HV k 340 or 270 k HV k 340 or 270 k HV k 340 or 270 k HV k 340 20 Impact strength Izod ft lbf U25 U15 U25 U15 29 Reference heat treatment Harden 1 000 C k k 1 020 C/OQ a + Temp
23、er 640 C k k 660 C/OQ or WQ a + Temper 620 C k k 640 C/OQ or WQ a 44 External defects BS S 100, Section 5 BS S 100, Section 1 50 Macro and micro-cleanness BS S 100, Section 1 and Annex A BS S 100, Section 1 and Annex A 61 Internal defects BS S 100, Section 1 and Annex B BS S 100, Section 1 and Annex
24、 B Ultrasonic testing 97 Product and condition designation S 80A S 80C 98 NOTE a The tolerance on the selected temperature shall be 10 C.BS 7S 80:2002 BSI 5 March 2004 3 Table 2 Technical requirements for high chromium-nickel corrosion resisting steel bars, D ek 100 mm 1 Material designation BS S 80
25、 2 Chemical Element C Si Mn P S Cr Mo Ni Co Cu Nb Sn Ti V W Fe C o m p o s i t i o n m i n .0 . 1 21 5 . 02 . 0 Base % max. 0.20 1.0 1.0 0.030 0.025 18.0 0.30 3.0 0.05 0.30 0.05 0.02 0.05 0.20 0.05 3 Method of melting Air melted by an electric process 4.1 Form Bars Black bars Bright bars 4.2 Method
26、of production Forged or rolled Forged or rolled b Forged or rolled; cold drawn, cold rolled machined or ground b 4.3 Limit dimensions mm D ek 100 D ek 100 5.1 Technical specification BS S 100, Sections 1 and 2 BS S 100, Sections 1 and 3 BS S 100, Sections 1 and 3 6.1 Delivery condition Softened Hard
27、ened and tempered Hardened and tempered Heat treatment 650 C k a 1 000 C k k 1 020 C/OQ a 1 000 C k k 1 020 C/OQ a640 C k k 660 C/OQ or WQ a640 C k k 660 C/OQ or WQ a620 C k k 640 C/OQ or WQ ab620 C k k 640 C/OQ or WQ ab 7 Use condition Hardened and tempered Delivery condition Delivery condition Hea
28、t treatment 1 000 C k k 1 020 C/OQ a 640 C k k 660 C/OQ or WQ a620 C k k 640 C/OQ or WQ a Characteristics 8.1 Test sample Condition of supply BS S 100, Section 2 BS S 100, Section 3 8.2 Test piece BS S 100, Section 2 BS S 100, Section 3 8.3 Heat treatment See line 29 Delivery condition 9 Dimensions
29、concerned mm D ek 63 63 D ek 100 D ek 63 63 D ek100 D ek63 63 D ek 100 11 Direction of test piece L L L L 12 T Temperature C Ambient 13 Proof stress R p0,2 MPa U690 U690 U690 U690 14 Strength R m MPa 880 k R mk 1 080 880 k R mk 1 080 880 k R mk 1 080 880 k R mk 1 080 15 Elongation A % U12 U12 U12 U1
30、2 16 Reduction of area Z % 17 Hardness k277 HV 255 k HB k 321 255 k HB k 321 255 k HB k 321 255 k HB k 321 or 270 k HV k 340 or 270 k HV k 340 or 270 k HV k 340 or 270 k HV k 340 20 Impact strength Izod ft lbf U25 U15 U25 U15 U25 U15 29 Reference heat treatment Harden 1 000 C k k 1 020 C/OQ a + Temp
31、er 640 C k k 660 C/OQ or WQ a + Temper 620 C k k 640 C/OQ or WQ a 44 External defects BS S 100, Section 1 BS S 100, Section 1 BS S 100, Section 1 50 Macro and micro-cleanness BS S 100, Section 1 and Annex A BS S 100, Section 1 and Annex A BS S 100, Section 1 and Annex A 61 Internal defects BS S 100,
32、 Section 1 and Annex B BS S 100, Section 1 and Annex B BS S 100, Section 1 and Annex B Ultrasonic testing 97 Product and condition designation S 80E S 80B S 80D 98 NOTES a The tolerance on the selected temperature shall be 10 C. b Hardened and tempered bars which have been subjected to a cold rollin
33、g or cold straightening operation after the final tempering operation shall be stress-relieved at a temperature of between 300 C and 350 C and cooled in air.BS 7S 80:2002 4 BSI 5 March 2004 Annex A (informative) Steel of the compositional type covered by S 80 is particularly sensitive to the phenome
34、non of temper embrittlement. This is believed to be due to the segregation, by precipitation, of certain elements, notably phosphorus, to grain boundaries, which can occur when the steel is exposed to temperatures in the range of 350 C to 600 C. This temper embrittlement is thought to follow classic
35、al “C-curve” behaviour of nucleation and growth, in which growth, which gives the detrimental characteristics, is controlled by solid-state diffusion and is thus time-dependent. Available data suggests that prolonged exposure in the temperature range 450 Cto58 0 C is particularly damaging for this s
36、teel and can result in abnormally low impact strengths. Such exposure is most likely to occur in cooling following one of the tempering operations or during the tempering operation itself, especially if the heat treatment load is large or heat transfer is otherwise poor, because of bundling, etc. Re
37、vision BS 6S 80 of this standard introduced oil quenching following austenitization and oil or water quenching following the tempering stages. It also raised the temperature of the second temper and introduced a specific stress relieving temperature range, for work-hardened bar, which was below the
38、damaging temperature regime. Unfortunately, further instances of below specification impact properties, especially with small section, long wrought bar, have been encountered. Investigations concluded that these were due to processing indiscipline, where, because of the features mentioned above, bar
39、s had been subject to abnormally long exposure in the damaging temperature range. It was thus considered necessary to revise the standard, providing, with this issue, BS 7S 80, some informative guidance as well as removing the note in the table for bar dealing with bundling of bars. The following re
40、commendations are made. 1) Where practicable, bars should be effectively spaced for all stages of hardening and tempering. Where effective spacing is impractical, for example in bars of small D e , and where close bundling or layering is used, load masses should be such that heating and cooling rate
41、s closely approximate those of a single bar of D e k 63 mm. 2) Where bars are not effectively spaced for heat treatment the manufacturer should ensure that the selection of the impact test sample is made from those bars and position along the bar considered most at risk to damaging exposure. For exa
42、mple in tight bundles the mid length of a middle bar should be selected. 3) The manufacturer is encouraged to use statistical process control in which impact test results are considered. Current evidence suggests that for bar sizes, D e k 35 mm, correctly processed bar will typically have impact str
43、engths above 50 ft lbf. Where, on such bar sizes, impact strengths close to specification minimum, 25 to 35 ft lbf, are found, further confirmatory testing has often discovered bars or positions along bars having impact strengths below specification minimum.BS 7S 80:2002 BSI 5 March 2004 5 Bibliogra
44、phy BS 5555, Specification for SI units and recommendations for the use of their multiples and of certain other units. BS 5775-0, Specification for quantities, units and symbols Part 0: General principles. prEN 4500-1:1996, Metallic materials Rules for drafting and presentation of material standards
45、 Part 1: General rules. prEN 4500-5:1996, Metallic materials Rules for drafting and presentation of material standards Part 5: Specific rules for steels.BS 7S 80:2002 BSI 389 Chiswick High Road London W4 4AL BSI British Standards Institution BSI is the independent national body responsible for prepa
46、ring British Standards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter. Revisions British Standards are updated by amendment or revision. Users of British Standards should make sure that they possess the latest amendments or edition
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