ISO 4996-2014 Hot-rolled steel sheet of high yield stress structural quality《高屈服应力结构质量的热轧薄钢板》.pdf

1、 ISO 2014 Hot-rolled steel sheet of high yield stress structural quality Tles lamines chaud en acier de construction haute limite dlasticit INTERNATIONAL STANDARD ISO 4996 Fifth edition 2014-12-15 Reference number ISO 4996:2014(E) ISO 4996:2014(E)ii ISO 2014 All rights reserved COPYRIGHT PROTECTED D

2、OCUMENT ISO 2014 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission

3、 can be requested from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ISO 4996:2014(E)Contents Pa

4、ge Foreword iv 1 Scope . 1 2 Normative references 1 3 T erms and definitions . 1 3.4 Edges 2 4 Dimensions . 2 5 Conditions of manufacture 2 5.1 Steelmaking . 2 5.2 Chemical composition 2 5.3 Chemical analysis 2 5.3.1 Heat analysis 2 5.3.2 Product analysis . 3 5.4 Weldability 4 5.5 Application . 4 5.

5、6 Mechanical properties 4 5.7 Surface condition 4 5.8 Oiling 4 6 Dimensional and shape tolerances . 5 7 Tensile test sampling . 5 8 Tensile test 5 9 Retests . 5 9.1 Machining and flaws. 5 9.2 Elongation . 6 9.3 Additional tests . 6 10 Resubmission . 6 11 Workmanship 6 12 Inspection and acceptance .

6、6 13 Coil size . 6 14 Marking 7 15 Information to be supplied by the purchaser. 7 Bibliography 8 ISO 2014 All rights reserved iii ISO 4996:2014(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of

7、 preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental

8、 in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. The procedures used to develop this document and those intended for its further maintenance are described in the IS

9、O/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2. www.iso.org/directives Attention is drawn to the possibility th

10、at some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent d

11、eclarations received. www.iso.org/patents Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement. For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information ab

12、out ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information The committee responsible for this document is ISO/TC 17, Steel, Subcommittee SC 12, Continuous mill flat rolled products. This fifth edition cancels and repl

13、aces the fourth edition ( ISO 4996:2007), which has been technically revised.iv ISO 2014 All rights reserved Hot-rolled steel sheet of high yield stress structural quality 1 Scope This International Standard applies to hot-rolled steel sheet of high yield stress structural quality with the use of mi

14、croalloying elements. The product is intended for structural purposes where particular mechanical properties are required. It is generally used in the delivered condition and is intended for structures that may include bolting, riveting and welding. Because of the combination of higher strength and

15、microalloy composition, it is possible to obtain savings in mass, along with better formability and weldability as compared with steel sheet without microalloying elements. The product is produced on a wide strip-mill, not a plate mill. This International Standard does not cover steels intended for

16、boilers or pressure vessels, steels designated as commercial quality or drawing quality (covered by ISO 3573), steels to be re-rolled to cold-reducing products, steels designated as weathering steels, having increased atmospheric corrosion resistance, or steels having improved formability properties

17、 compared with those in this International Standard. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable to its application. For dated references, only the edition cited applies. For undated references, the latest edi

18、tion of the referenced document (including any amendments) applies. ISO 6892-1, Metallic materials Tensile testing Part 1: Method of testing at ambient temperature ISO 16160, Hot-rolled steel sheet products Dimensional and shape tolerances 3 T erms a nd definiti ons For the purposes of this document

19、 the following terms and definitions apply. 3.1 microalloying element element, such as niobium, vanadium, titanium, etc., added singly or in combination to obtain higher strength levels combined with better formability, weldability and toughness compared to non-alloyed steel produced to equivalent

20、strength levels 3.2 hot-rolled steel sheet product obtained by rolling heated steel through a continuous-type or reversing-type wide strip-mill to the required sheet thickness, the product having a surface covered with oxide or scale resulting from the hot-rolling operation 3.3 hot-rolled descaled s

21、teel sheet hot-rolled steel sheet from which oxide or scale has been removed, commonly by pickling in an acid solution Note 1 to entry: Descaling may also be performed by a mechanical means such as grit blasting. Some changes in properties may result from descaling. INTERNATIONAL ST ANDARD ISO 4996:

22、2014(E) ISO 2014 All rights reserved 1 ISO 4996:2014(E) 3.4 Edges 3.4.1 mill edge normal side edge without any definite contour produced in hot rolling Note 1 to entry: Mill edges may contain some irregularities such as cracked or torn edges or thin (feathered) edges. 3.4.2 sheared edge normal edge

23、obtained by shearing, slitting or trimming a mill edge product Note 1 to entry: Normal processing does not necessarily provide a definite positioning of the slitting burr. 3.5 aluminum killed steel which has been deoxidized with aluminum sufficient to prevent the evolution of gas during solidificati

24、on 3.6 lot 50 t or less of sheet of the same grade and class rolled to the same thickness and condition 4 Dimensions 4.1 This product is commonly produced in thicknesses from 1,6 mm to 6 mm and in widths of 600 mm and over, in coils and cut lengths. 4.2 Hot-rolled sheet less than 600 mm wide may be

25、slit from wide sheet and will be considered sheet. NOTE Hot-rolled sheet up to but not including 3 mm in thickness is commonly known as “sheet”. Hot-rolled sheet 3 mm and over in thickness is commonly known as either “sheet” or “plate”. 5 Conditions of manufacture 5.1 Steelmaking Unless otherwise ag

26、reed by the interested parties, the processes used in making the steel and in manufacturing hot-rolled sheet are left to the discretion of the manufacturer. On request, the purchaser shall be informed of the steelmaking process being used. 5.2 Chemical composition The chemical composition (heat anal

27、ysis) shall not exceed the values given in Tables 1 and 2. 5.3 Chemical analysis 5.3.1 Heat analysis An analysis of each heat shall be made by the manufacturer in order to determine compliance with the requirements given in Tables 1 and 2. On request, at the time of ordering, this analysis shall be

28、reported to the purchaser or the purchasers representative. Each of the elements listed in Table 2 shall be included in the report of the heat analysis.2 ISO 2014 All rights reserved ISO 4996:2014(E) Table 1 Chemical composition (heat analysis) Mass fractions in percent Grade C max. Mn max. Si max.

29、P max. S max. HS355 0,20 1,60 0,50 0,035 0,035 HS390 0,20 1,60 0,50 0,035 0,035 HS420 0,20 1,70 0,50 0,035 0,035 HS460 0,20 1,70 0,50 0,035 0,035 HS490 0,20 1,70 0,50 0,035 0,035 Each grade contains one or more microalloying elements with the following restrictions: Ti 0,10 % max., Nb 0,08 % max., V

30、 0,10 % max The amounts of these elements are subject to agreement between the manufacturer and purchaser. In the absence of an agreement, the amounts shall be at the discretion of the manufacturer. In all cases, the sum of Ti, Nb, and V shall be less than or equal to 0,22 %. In no case shall Nb, V

31、or Ti be less than 0,005 %. Table 2 Limits on additional chemical elements Mass fractions in percent Element Heat analysis max. Product analysis max. Cu b Ni b 0,20 0,20 0,23 0,23 Cr bc 0,15 0,19 Mo bc 0,06 0,07 aEach of the elements listed in this table shall be included in the report of the heat a

32、nalysis. When the amount of copper, nickel, chromium or molybdenum present is less than 0,02 %, the analysis may be reported as “0,15 0,40 0,03 0,04 Mn 0,60 0,60 1,15 1,15 1,70 0,03 0,04 0,05 NOTE The above maximum tolerance is the allowable excess over the specified requirement and not the heat ana

33、lysis. For example, for Grade HS490, the following product analysis values are within these tolerances: C 0,24 %, Mn 1,75 %, P 0,045 %, S 0,045 %, Si 0,54 %. ISO 2014 All rights reserved 3 ISO 4996:2014(E) Element R a n g e o f s p e c i f ie d e le m e n t Tolerance over maximum speci- f ie d P 0,0

34、4 0,010 S 0,04 0,010 Si 0,30 0,30 0,50 0,03 0,04 N 0,030 0,005 NOTE The above maximum tolerance is the allowable excess over the specified requirement and not the heat analysis. For example, for Grade HS490, the following product analysis values are within these tolerances: C 0,24 %, Mn 1,75 %, P 0,

35、045 %, S 0,045 %, Si 0,54 %. 5.4 Weldability The product is suitable for welding if appropriate welding conditions are selected. For undescaled steel, it may be necessary to remove the scale or oxide, depending upon the welding method. As the carbon content increases above 0,15 %, spot welding becom

36、es increasingly difficult. 5.5 Application It is desirable that the specified product be identified for fabrication by the name of the part or by the intended application, which shall be compatible with the grade specified. Proper identification of the part may include visual examination, prints or

37、description, or a combination of these. 5.6 Mechanical properties At the time that the steel is made available for shipment, the mechanical properties shall be as stated in Table 4, if they are determined on test pieces obtained in accordance with the requirements of Clause 7. 5.7 Surface condition

38、Oxide or scale on hot-rolled steel sheet is subject to variations in thickness, adherence and colour. Removal of the oxide or scale by pickling or blast cleaning may disclose surface imperfections not readily visible prior to this operation. 5.8 Oiling As a deterrent to rusting, a coating of oil is

39、usually applied to hot-rolled descaled steel sheet, but sheet may be furnished not oiled if required. The oil is not intended as a forming lubricant and shall be easily removable using degreasing chemicals. On request, the manufacturer shall advise the purchaser of the type of oil used. Hot-rolled d

40、escaled sheet may be ordered not oiled, if required, in which case the supplier has limited responsibility if oxidation occurs.Table 3 (continued) 4 ISO 2014 All rights reserved ISO 4996:2014(E) Table 4 Mechanical properties Grade R emin. a MPa R mmin. (information only) MPa A min., % b e 3 3 e 6 L

41、o= 50 mm L o= 80 mm L o= 5,65 S o L o= 50 mm HS355 355 430 18 16 22 21 HS390 390 460 16 14 20 19 HS420 420 490 14 12 19 18 HS460 460 530 12 10 17 16 HS490 490 570 10 8 15 14 R e= yield strength may be either R eLor R eH , but not both R eH= upper yield strength R eL= lower yield strength R m= tensil

42、e strength A = percentage elongation after fracture L o= initial gauge length on test piece S o= original cross-sectional area of gauge length e = thickness of steel sheet, in millimetres 1MPa = 1N/mm 2 aThe yield strength values can be measured by 0,5 % elongation proof strength (proof strength und

43、er load) or by 0,2 % offset when a definite yield phenomenon is not present. bFor thicknesses up to 3 mm, use either L o= 50 mm or L o= 80 mm. For thicknesses from 3 mm to 6 mm, use either L o= 5,65 S oor L o= 50 mm. In case of dispute, however, only the results obtained on a proportional test piece

44、 will be valid for material 3 mm and over in thickness. 6 Dimensional and shape tolerances Dimensional and shape tolerances applicable to hot-rolled steel sheet of high yield stress structural quality shall be as given in ISO 16160. These tolerances also apply to descaled material. 7 Tensile test sa

45、mpling One representative sample for the tensile test required in Table 4 shall be taken from each lot of sheet for shipment. 8 Tensile test The tensile test shall be carried out in accordance with ISO 6892-1. Transverse test pieces shall be taken midway between the centre and edge of the sheet as r

46、olled. 9 Retests 9.1 Machining and fla w s If any test piece shows defective machining or develops flaws, it shall be discarded and another test piece shall be substituted. ISO 2014 All rights reserved 5 ISO 4996:2014(E) 9.2 Elongation If the percentage elongation of any test piece is less than that

47、 specified in Table 4, and if any part of the fracture is outside the middle half of the gauge length as scribed before the test, the test shall be discarded and a retest shall be carried out. 9.3 Additional tests If a test does not give the specified results, two additional tests shall be carried o

48、ut at random on the same lot. Both tests shall conform to the requirements of this international standard; otherwise the lot shall be rejected. 10 Resubmission 10.1 The manufacturer may resubmit, for acceptance, the products that have been rejected during earlier inspection because of unsatisfactory

49、 properties, after the rejected products have been subjected to a suitable treatment (selection, heat treatment, etc.) which, on request, will be indicated to the purchaser. In this case, tests shall be carried out as if they applied to a new lot. 10.2 The manufacturer has the right to present the rejected products to a new examination for compliance with the requirements for another grade. 11 Workmanship 11.1 The surface condition shall be that normally obtained in a hot-rolled or hot-rolled and descaled pro