1、 ISO 2013 Hot-rolled steel sheet of higher yield strength with improved formability Tles en acier lamines chaud limite dlasticit et aptitude au formage accrues INTERNATIONAL STANDARD ISO 5951 Fifth edition 2013-06-01 Reference number ISO 5951:2013(E) ISO 5951:2013(E)ii ISO 2013 All rights reserved C
2、OPYRIGHT PROTECTED DOCUMENT ISO 2013 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 pe
3、rmission. Permission 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 595
4、1:2013(E) ISO 2013 All rights reserved iii Contents Page Foreword iv 1 Scope . 1 2 Normative references 1 3 T erms and definitions . 1 4 Dimensions . 2 5 Conditions of manufacture 2 5.1 Steelmaking . 2 5.2 Chemical composition 2 5.3 Chemical analysis 3 5.4 Weldability 4 5.5 Application . 4 5.6 Mecha
5、nical properties 4 5.7 Surface condition 5 5.8 Oiling 5 6 Dimensional and shape tolerances . 5 7 Sampling Tensile test 6 8 Mechanical property tests 6 8.1 Tensile test 6 8.2 Impact test 6 9 Retests . 6 9.1 Machining and flaws. 6 9.2 Elongation . 6 9.3 Additional tests . 6 10 Resubmission . 6 11 Work
6、manship 6 12 Inspection and acceptance . 7 13 Coil size . 7 14 Marking 7 15 Information to be supplied by the purchaser. 7 Bibliography 9 ISO 5951:2013(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The
7、 work of 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-gove
8、rnmental, 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. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. T
9、he main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vot
10、e. Attention is drawn to the possibility that 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. ISO 5951 was prepared by Technical Committee ISO/TC 17, Steel, Subcommittee SC 12, Continuous mill
11、 flat rolled products. This fifth edition cancels and replaces the fourth edition ( ISO 5951:2008), which has been technically revised.iv ISO 2013 All rights reserved INTERNATIONAL ST ANDARD ISO 5951:2013(E) Hot-rolled steel sheet of higher yield strength with improved formability 1 Scope 1.1 This I
12、nternational Standard applies to all grades of hot-rolled steel sheet of higher yield strength with improved formability. The steel is killed, made according to a fine grain practice and has a suitable chemical composition, including microalloying elements, to provide improved formability. The produ
13、ct is intended for the fabrication of parts requiring better formability than is provided by normal high yield strength steel sheet. It is generally used in the delivered condition. 1.2 Because of the combination of higher strength and improved formability, it is possible to obtain savings in mass a
14、long with better weldability. 1.3 This International Standard does not cover steel intended for boilers or pressure vessels, steels designated as commercial quality or drawing quality (covered in ISO 3573), steels designated as weathering steels, having increased atmospheric corrosion resistance, or
15、 lower yield strength steels having less formability compared with those in this International Standard (covered in ISO 4995 and ISO 4996). 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited a
16、pplies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 148-1, Metallic materials Charpy pendulum impact test Part 1: Test method ISO 6892-1, Metallic materials Tensile testing Part 1: Method of test at room temperature ISO 16160, Hot-rol
17、led steel sheet products Dimensional and shape tolerances ISO 20805, Hot-rolled steel sheet in coils of higher yield strength with improved formability and heavy thickness for cold forming 3 T erms a nd definiti ons For the purposes of this document, the following terms and definitions apply. 3.1 mi
18、croalloying element element, such as niobium, vanadium, titanium, added singly or in combination to obtain higher strength levels combined with better formability, weldability and toughness as compared with non-alloyed steel produced to equivalent strength levels 3.2 hot-rolled steel sheet product o
19、btained by rolling heated steel through a continuous hot strip mill or other hot rolling processes that produce a coiled product to the required sheet thickness and tolerances Note 1 to entry: The product has a surface covered with oxide or scale resulting from the hot rolling operation. ISO 2013 Al
20、l rights reserved 1 ISO 5951:2013(E) 3.3 hot-rolled descaled steel 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 mechanical means such as grit blasting. Some change in properties c
21、an result from descaling. 3.4 mill edge normal 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. 3.5 sheared edge normal edge obtained by shearing, slitting or trimming a mill
22、 edge product Note 1 to entry: Normal processing does not necessarily provide a definite positioning of the slitting burr. 4 Dimensions 4.1 Hot-rolled sheet less than 600 mm wide may be slit from wide sheet and will be considered as sheet. NOTE Hot-rolled sheet up to but not including 3 mm in thickn
23、ess is commonly known as sheet. Hot-rolled sheet 3 mm and over in thickness is commonly known as either “sheet” or “plate”. 4.2 This product is commonly produced in the range of thicknesses of 1 mm to 6 mm and in widths of 600 mm and over, in coils and cut lengths. 5 Conditions of manufacture 5.1 St
24、eelmaking Unless otherwise agreed upon 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 5
25、.2.1 For all grades, the chemical composition (heat analysis) shall conform to the requirements in Tables 1 and 2. 5.2.2 The steel covered by this International Standard shall contain microalloying elements. The chemical composition may be agreed between the interested parties at the time of enquiry
26、 and ordering.2 ISO 2013 All rights reserved ISO 5951:2013(E) Table 1 Chemical analysis (heat analysis) Mass fractions in percent Element Heat analysis max. Carbon 0,15 Manganese 1,65 Phosphorus 0,025 Sulfur 0,030NOTE 1 As the form of sulfide inclusions may have a certain influence on the cold formi
27、ng properties of the products, manufacturers may, at their discretion, influence the form of inclusions by adding certain elements, such as Ce or Ca, or may choose a very low sulfur content for these steels.NOTE 2 These steels shall also contain one or more of the following microalloying elements: v
28、anadium, titanium or niobium. Other alloying elements may be present but are not required. Table 2 Limits on additional chemical elements Mass fractions in percent Element Heat analysis max. Product analysis max. Copper 0,20 0,23 Nickel 0,20 0,23 Chromium 0,15 0,19 Molybdenum 0,06 0,07 5.3 Chemical
29、analysis 5.3.1 Heat analysis An analysis of each heat of steel shall be made by the manufacturer to determine the contents of carbon, manganese, phosphorus and sulfur, and the content of other elements giving the specified mechanical strength and formability. On request, this analysis shall be repor
30、ted to the purchaser or his representative. 5.3.2 Product analysis A product analysis may be made by the purchaser to verify the specified analysis of the product and shall take into consideration any normal heterogeneity. For killed steels, the sampling method shall be agreed upon between the inter
31、ested parties at the time of ordering. The product analysis tolerances shall be in accordance with Tables 2 and 3. ISO 2013 All rights reserved 3 ISO 5951:2013(E) Table 3 Product analysis tolerances Mass fractions in percent Element Maximum of s p e c i f ie d e le m e n t Tolerance over m a x i m u
32、 m s p e c i f ie d Carbon 0,15 0,03 Manganese 1,65 0,05 Phosphorus 0,025 0,010 Sulfur 0,030 0,010NOTE The above maximum tolerance is the allowable excess over the specified requirement and not the heat analysis. For example, for all grades in this International Standard, the following product analy
33、sis values are within these tolerances: C 0,18 %, Mn 1,70 %, P 0,035 %, S 0,040 %. 5.4 Weldability This product is normally suitable for welding when appropriate welding conditions are selected. For undescaled steel, it may be necessary to remove the scale or oxide depending upon the welding method.
34、 5.5 Application It is desirable that hot-rolled steel sheet be identified for fabrication by name of the part or by the intended application. Proper identification of the part may include visual examination, prints or description, or a combination of these. 5.6 Mechanical properties At the time tha
35、t the steel is made available for shipment, the mechanical properties shall be as stated in Table 4 when they are determined on test pieces in accordance with the requirements of Clause 8. Any additional property requirements specified or required are subject to agreement between the interested part
36、ies at the time of enquiry and ordering. Such additional requirements may include characterization or prescribed values for properties such as impact for sheet over 6 mm in thickness (see 8.2).4 ISO 2013 All rights reserved ISO 5951:2013(E) Table 4 Mechanical properties Grade R emin a MPa R mmin (in
37、formation only) MPa A min. b, c e 3 mm 3 mm e 6 mm L o= 50 mm L o= 80 mm = L o= 50 mm HSF325 325 410 22 20 25 24 HSF355 355 420 21 19 24 23 HSF420 420 480 18 16 21 20 HSF490 490 540 15 13 18 17 HSF560 560 610 12 10 15 14 R e= yield strength R m= tensile strength A = percentage elongation after fract
38、ure e = thickness of steel sheet, in millimetres L o= gauge length on test piece S o= original cross sectional area of gauge length 1 MPa = 1 N/mm 2 aThe yield strength can be measured either by 0,5 % elongation proof stress R t0,5(proof stress under load) or by 0,2 % offset R p0,2when a definite yi
39、eld phenomenon is not present. bFor thicknesses e3 mm, use either L o= 50 mm or L o= 80 mm. For thicknesses of 3 mm and over, use = or L o= 50 mm. In case of dispute, only the results obtained on a 50 mm test piece will be valid. cFor material over 6 mm in thickness, values for elongation are subjec
40、t to agreement between the manufacturer and the purchaser. 5.7 Surface condition 5.7.1 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 visi
41、ble prior to this operation. 5.7.2 The steel shall be supplied as rolled or pickled and oiled as requested by the purchaser at the time of enquiry and ordering. 5.8 Oiling As a deterrent to rusting, a coating of oil is usually applied to hot-rolled descaled steel sheet. The oil is not intended as a
42、drawing or forming lubricant and should be easily removable with degreasing chemicals. The product may be ordered not oiled, if required, in which case, the supplier has limited responsibility if oxidation occurs. 6 Dimensional and shape tolerances Dimensional and shape tolerances applicable to hot-
43、rolled steel sheet of higher yield strength with improved formability shall be as given in ISO 16160. These tolerances also apply to descaled material. Tolerances on coiled material with thicknesses over 6 mm shall be as given in ISO 20805. ISO 2013 All rights reserved 5 ISO 5951:2013(E) 7 Sampling
44、Tensile test One representative sample for the tensile test required in Table 4 shall be taken from each lot of sheet for shipment. A lot consists of 50 t or less of sheet of the same designation rolled to the same thickness and condition. 8 Mechanical property tests 8.1 Tensile test The tensile tes
45、t 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 rolled. 8.2 Impact test While not usually specified, if so agreed at the time of ordering, impact tests may be specified for material over 6 mm in thickness.
46、 The test piece shall be in the longitudinal direction and the test shall be carried out in accordance with ISO 148-1. 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 piece substituted. 9.2 Elongation If the percent
47、age elongation of any test piece is less than that 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 specifie
48、d results, two more tests shall be carried out at random on the same lot. Both retests 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
49、 earlier inspection because of unsatisfactory properties, after he has subjected them to a suitable treatment, (for example: selection, heat treatment), which, on request, will be indicated to the purchaser. In this case, the tests should be carried out as if they applied to a new batch. 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 obtai
