JIS G 3106 - 2015

JAPANESE INDUSTRIAL STANDARD Translated and Published by Japanese Standards Association JIS G 3106: 2015 (JISF) Rolled steels for welded structure ICS 25.160.01;77.140.01;77.140.10 Reference number: JIS G 3106 : 2015 (E) PROTECTED BY COPYRIGHT 15 S G 3106 : 2015 Date of Establishment: Date of Revision: 1952-11-25 2015-08-20 Date of Public Notice in Official Gazette: Investigated by: 2015-08-20 Japanese Industrial Standards Committee Standards Board for ISO area Technical Committee on Metal and Inorganic Materials JIS G 3106: 2015, First English edition published in 2015-11 Translated and published by: Japanese Standards Association Mita MT Building, 3-13-12, Mita, Minato-ku, Tokyo, 108-0073 JAPAN In the event of any doubts arising as to the contents, the original JIS is to be the final authority © JSA 2015 All rights reserved Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher Printed in Japan HT/HN PROTECTED BY COPYRIGHT G 3106 : 2015 Contents Page Introduction································································································· 1 Scope ···········································1 Normative references············································································ Classification, symbols and applicable thicknesses ····································2 Chemical composition 5.1 5.2 Heat treatment and symbol of heat treatment ··········································4 Heat treatment···················································································· Symbol of heat treatment······································································ 6.1 6.2 Carbon equivalent and weld-crack sensitivity composition·························· Carbon equivalent and weld-crack sensitivity composition for SM570 ···········4 Carbon equivalent and weld -crack sensitivity composition for steel plates and sheets manufactured by thermo-mechanical control process ········5 Mechanical properties· 7.1 7.2 Yield point or proof stress, tensile strength and elongation ·······5 Charpy absorbed energy········································································ Shape, dimensions, mass and tolerances·················································· Appearance 10 10.1 10.2 Tests················································· ·················································6 Chemical analysis················································································ Mechanical tests·················································································· 11 Inspection························································································· ·10 12 Reinspection ··10 13 Marking ·10 14 Report····· ····································11 Annex JA (normative) Chemical composition and tensile properties of steel plates and sheets agreed between the purchaser and the manufacturer ·12 Annex JB (normative) Mechanical properties of sections with side under 40 mm and of flats with width under 40 mm ·······················14 Annex JC (normative) Quality requirements for hot extruded sections·············· ·15 Annex JD (informative) Comparison table between JIS and corresponding International Standards ·············································19 (i) PROTECTED BY COPYRIGHT G 3106 : 2015 Foreword This translation has been made based on the original Japanese Industrial Standard revised by the Minister of Economy, Trade and Industry through deliberations at the Japanese Industrial Standards Committee as the result of proposal for revision of Japanese Industrial Standard submitted by The Japan Iron and Steel Federation (JISF) with the draft being attached, based on the provision of Article 12 Clause of the Industrial Standardization Law applicable to the case of revision by the provision of Article 14 Consequently JIS G 3106:2008 is replaced with this Standard However, JIS G 3106:2008 may be applied in the JIS mark certification based on the relevant provisions of Article 19 Clause 1, etc of the Industrial Standardization Law until August 19, 2016 This JIS document is protected by the Copyright Law Attention is drawn to the possibility that some parts of this Standard may conflict with patent rights, applications for a patent after opening to the public or utility model rights The relevant Minister and the Japanese Industrial Standards Committee are not responsible for identifying any of such patent rights, applications for a patent after opening to the public or utility model rights PROTECTED BY COPYRIGHT JAPANESE INDUSTRIAL STANDARD JIS G 3106: 2015 Rolled steels for welded structure Introduction This Japanese Industrial Standard has been prepared based on the first editions of ISO 630-1 and ISO 630-2 published in 2011, and the first edition of ISO 630-3 published in 2012 with some modifications of the technical contents The portions given continuous sidelines or dotted underlines are the matters in which the contents of the corresponding International Standards have been modified A list of modifications with the explanations is given in Annex JD Scope This Standard specifies the hot rolled steels and hot extruded sections used for welded structure such as bridges, ships, rolling stock, petroleum storage tanks, containers and other structures with especially high weldability (hereafter referred to as "steel products") The quality requirements for hot extruded sections are given in Annex JC NOTE: The International Standards corresponding to this Standard and the symbol of degree of correspondence are as follows ISO 630-1 : 2011 Structural steels - Part : General technical delivery conditions for hot-rolled products ISO 630-2 : 2011 Structural steels - Part : Technical delivery conditions for structural steels for general purposes ISO 630-3 : 2012 Structural steels - Part : Technical delivery conditions for fine-grain structural steels (overall evaluation: MOD) In addition, symbols which denote the degree of correspondence in the contents between the relevant International Standards and JIS are IDT (identical), MOD (modified), and NEQ (not equivalent) according to ISO/lEe Guide 21-1 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this Standard The most recent editions of the standards (including amendments) indicated below shall be applied JJS_J! O_9_2.Q _ $t;~n[fl!!:d_t£!§_t;_mf!tllQfl_{(rrll~!J:t_!!!1!J:Jy$i$flf$t;f!~.!P!:Qfly~t$ JJS_J! OJ.Q1 _ $t;~£!I~nd§t~_~lp.J;Qdl!.f;_t~_~_fl:f!!H~!:~lt£!/!h!1i~EJld?liy~!'y};:~gJ.!i!:~!!J~1J.t~ JJSJ! Q415 _ $t;~~l~nd§t~_~Ip.J;Qdl:.lf;_t~_~_11J$p?~t;jQn_[!p[!YJn~!1t$ JJS_- 50:::; 100 :::;0.47 >100 As agreed between the purchaser and the manufacturer b) The weld -crack sensitivity composition may be applied in place of the carbon equivalent by agreement between the purchaser and the manufacturer In this case, the weld-crack sensitivity composition shall be determined by formula (2) using the heat analysis value in 10.1, and the value shall be as given in Table PROTECTED BY COPYRIGHT G 3106: 2015 P, Si 30 CM where, Mn 20 Cu 20 Ni 60 Cr 20 Mo 15 V 10 ( ) =C+-+-+-+-+-+-+-+5B ····························2 PCM : weld·crack sensitivity composition (%) Table Thickness mm Weld·crack sensitivity composition % Weld-crack sensitivity composition :::;50 :::;0.28 > 50:::; 100 :::;0.30 >100 As agreed between the purchaser and the manufacturer 6.2 Carbon equivalent and weld-crack sensitivity composition for steel plates and sheets manufactured by thermo-mechanical control process For steel plates and sheets manufactured by thermo-mechanical control process as agreed between the purchaser and the manufacturer, the carbon equivalent, or alternatively, the weld-crack sensitivity composition applied by agreement shall be as follows a) Carbon equivalent The carbon equivalent shall be determined by formula (1) of 6.1 using the heat analysis value in 10.1, and the value shall be as given in Table Table Carbon equivalent Unit: % SM490A SM490YA SM520B SM520C SM490B SM490YB SM490C :::;0.40 Applicable :::;50 mm :::;0.38 thickness a) >50 mm :::; 100 mm :::;0.42 :::;0.40 Note a) The carbon equivalent of steel plate/sheet of thickness over 100 mm shall be as agreed between the purchaser and the manufacturer Symbol of grade I I b) Weld-crack sensitivity composition The weld-crack sensitivity composition shall be determined by formula (2) of 6.1 using the heat analysis value in 10.1 and the value shall be as given in Table Table Weld-crack sensitivity composition Unit: % SM490A SM490YA SM520B SM520C SM490B SM490YB SM490C :::;0.24 :::;0.26 Applicable I :::;50 mm thickness a) I >50 mm :::; 100 mm :::;0.26 :::;0.27 Note a) The weld ·crack sensitivity composition of steel plate/sheet of thickness over 100 mm shall be as agreed between the purchaser and the manu· facturer Symbol of grade 7.1 Mechanical properties Yield point or proof stress, tensile strength and elongation PROTECTED BY COPYRIGHT G 3106 : 2015 Steel products shall be tested in accordance with 10.2, and the yield point or proof stress, tensile strength and elongation shall be as given in Table The yield point or proof stress, tensile strength and elongation of steel plate and sheet agreed between the purchaser and the manufacturer as specified in Note b) to Table shall be as given in Table JA.2 The yield point or proof stress, tensile strength and elongation of sections with a side under 40 mm and of flats with a width under 40 mm shall be as given in Table JB.1 7.2 Charpy absorbed energy Steel products of thickness over 12 mm given in Table shall be tested in accordance with 10.2, and the Charpy absorption energy shall be as given in Table In this case, the value of Charpy absorption energy shall be taken from the mean of three test pieces and shall be judged by 9.6 of JIS G 0404 Shape, dimensions, mass and tolerances The shape, dimensions, mass and tolerances of steel products shall be in accordance with JIS G 3192, JIS G 3193 and JIS G 3194 In this case, the tolerances on width of steel plate and sheet and cut-edged steel strip in coil as well as the tolerances on length of steel plate and sheet shall be in accordance with tolerance A specified in JIS G 3193, unless otherwise specified Appearance The appearance of steel products shall be in accordance with clause of JIS G 3192, clause of JIS G 3193 and clause 10 of JIS G 3194 Repair by welding of steel plate SM570 shall be previously agreed between the purchaser and the manufacturer 10 Tests 10.1 Chemical analysis The chemical analysis shall be as follows a) General requirements and sampling method General requirements for chemical analysis and the sampling method for heat analysis shall be in accordance with clause of JIS G 0404 b) Analysis method The heat analysis shall be in accordance with JIS G 0320 PROTECTED BY COPYRIGHT 11 G 3106: 2015 14 Report The manufacturer shall submit the inspection document to the purchaser The report shall be in accordance with clause 13 of JIS G 0404 Unless otherwise specified in the order, the type of the inspection document to be submitted shall be the standard designation 3.1 in Table of JIS G 0415 When Note a) to Table and Table JA.1 are applied, the content rate of the alloy element included shall be addressed in the report If the carbon equivalent or weld -crack sensitivity composition is applied, the content rate of the alloy element included in each formula shall be reported PROTECTED BY COPYRIGHT 12 G 3106 : 2015 Annex JA (normative) Chemical composition and tensile properties of steel plates and sheets agreed between the purchaser and the manufacturer JA.1 Application This Annex specifies the chemical composition and tensile properties of steel plates agreed between the purchaser and the manufacturer according to Note b) to Table JA.2 Chemical composition Steel plates and sheets agreed between the purchaser and the manufactured according to Note b) to Table shall be tested in accordance with 10.1, and the heat analysis value shall be as given in Table JA.1 Table Symbol of grade SM400A Thickness C Chemical composition a) Si Mn b) P Unit: % S 2::2.5 x C c) :::;0.25 >200 mm :::;0.035 :::;0.035 :::;450 mm :::;0.22 SM400B >200 mm :::;0.35 :::;0.035 :::;0.035 2::0.60 :::;250 mm >100 mm :::;0.18 :::;0.35 :::;0.035 :::;0.035 SM400C :::;250 mm :::;0.22 SM490A >200 mm :::;0.55 :::;0.035 :::;0.035 :::;300 mm :::;0.20 :::;0.55 SM490B >200 mm :::;0.035 :::;0.035 :::;250 mm >100 mm :::;0.18 :::;0.55 :::;0.035 :::;0.035 SM490C :::;250 mm :::;0.20 :::;0.55 SM490YA >100 mm :::;0.035 :::;0.035 :::;150 mm SM490YB :::;0.20 :::;0.55 SM520B >100 mm :::;0.035 :::;0.035 :::;150 mm SM520C >100 mm :::;0.18 :::;0.55 :::;0.035 :::;0.035 SM570 :::;150 mm Notes a) Alloy elements other than those specified in this table may be added as necessary b) The upper limit of manganese shall be as agreed between the purchaser and the manufacturer c) For the value of carbon, the heat analysis value shall be applied PROTECTED BY COPYRIGHT 13 G 3106: 2015 JA.3 Yield point or proof stress, tensile strength and elongation Steel plates agreed between the purchaser and the manufacturer according to Note b) to Table shall be tested in accordance with 10.2 and the yield point or proof stress, tensile strength and elongation shall be as given in Table JA.2 The tensile test piece shall be No.4 test piece Table JA.2 Symbol of grade Thickness Yield point or proof stress, tensile strength and elongation Yield point or proof stress N/mm Tensile strength N/mm Elongation % mm > 200:::; 450 SM400A 2::195 2::21 SM400B > 200:::; 250 400 to 510 > 100:::; 160 2::205 2::24 a) SM400C > 160:::; 250 2::195 > 200:::; 300 SM490A 2::275 2::20 > 200:::; 250 SM490B 490 to 610 > 100:::; 160 2::285 2::23 a) SM490C > 160:::; 250 2::275 SM490YA > 100:::; 150 2::21 a) 490 to 610 2::315 > 100:::; 150 SM490YB > 100:::; 150 SM520B 2::21 a) 520 to 640 2::315 SM520C > 100:::; 150 2::20 a) SM570 > 100:::; 150 570 to 720 2::410 NOTE: N/mm = MPa Note a) For the elongation of steel plate/sheet of thickness over 100 mm, subtract from the elongation values of this table for each increment of 25 mm or its fraction in thickness However, the subtraction shall not exceed PROTECTED BY COPYRIGHT 14 G 3106 : 2015 Annex JB (normative) Mechanical properties of sections with side under 40 mm and of flats with width under 40 mm JB.l Mechanical properties Sections with a side under 40 mm and flats with a width under 40 mm shall be tested in accordance with 10.2, and the yield point or proof stress, tensile strength and elongation shall be as given in Table JB.l Table JB.l Symbol of grade SM400A SM400B SM400C Mechanical properties of sections with side under 40 mm and of flats with width under 40 mm Yield point or proof stress N/mm Thickness mm :::;16 >16 :::;40 2:245 2:235 Tensile strength Thickness a) N/mm 400 to 510 mm 2:3:::;5 > 5:::; 16 > 16:::; 40 SM490A SM490B SM490C 2:325 2:315 490 to 610 2:3:::;5 > 5:::; 16 > 16:::; 40 SM490YA SM490YB 2:365 2:355 490 to 610 2:3:::;5 > 5:::; 16 > 16:::; 40 SM520B SM520C 2:365 2:355 520 to 640 2:3:::;5 > 5:::; 16 > 16:::; 40 SM570 2:460 2:450 570 to 720 2:3:::;5 > 5:::; 16 > 16:::; 40 Tensile test piece Elon· gation % No.5 No.14B No.5 No.14B No.5 No.14B No.5 No.14B No.5 No.14B No.5 No.14B No.5 No.14B No.5 No.14B No.5 No.14B No.5 No.14B No.5 No.14B No.5 No.14B No.5 No.14B No.5 No.14B No.5 No.14B 2:23 >23 2:28 2:26 >35 2:25 2:22 2:22 2:27 2:24 2:33 2:24 2:19 2:19 >24 2:22 2:30 >22 2:19 2:19 >24 2:22 2:30 >22 2:19 2:19 >19 2:17 2:26 >19 NOTE: N/mm = MPa Note a) For sections, the thickness of steel products shall be that of the location of test pieces PROTECTED BY COPYRIGHT 15 G 3106: 2015 Annex JC (normative) Quality requirements for hot extruded sections JC.1 Application This Annex specifies the quality of specially-shaped hot extruded sections to be used for construction components, coupling components for sheet piling, steel pipe sheet piles and the like Hot extruded sections shall be applied by agreement between the purchaser and the manufacturer JC.2 Classification, symbols and applicable dimensions Hot extruded sections are classified into 10 classes, and their symbols and applicable dimensions shall be as given in Table JC.l Table JC.1 Symbol of grade and applicable dimensions for hot extruded sections Symbol of grade SM400A SM400B SM400C SM490A SM490B SM490C SM490YA SM490YB SM520B SM520C JC.3 Applicable dimensions 2:5 mm in thickness :::;250 mm in side or height Manufacturing method The sections shall be manufactured by hot extrusion 1) Hot extruded sections shall be formed so that the forging ratio 2) is at least Notes JC.4 1) Hot extrusion means a forming method by which heated billets are extruded through the dice 2) The forging ratio here means a ratio of the cross-section area of a cast slab or a bloom to that after hot extrusion Chemical composition Hot extruded sections shall be tested in accordance with 10.1, and the heat analysis values shall be as given in Table PROTECTED BY COPYRIGHT 16 G 3106 : 2015 JC.5 JC.5.1 Mechanical properties The location of tensile and impact test pieces The location of tensile and impact test pieces of hot extruded sections shall be as agreed between the purchaser and the manufacturer However, the location of test pieces across the width of section shall be as follows a) The location of tensile test pieces across the width of section piece shall be taken at 114 of the width The No.4 tensile test b) The location of impact test pieces across the width of section The location of the impact test pieces across the width of section shall be as shown in Figure A.3 of JIS G 0416 JC.5.2 Yield point or proof stress, tensile strength and elongation Hot extruded sections shall be tested in accordance with 10.2, and the yield point or proof stress, tensile strength and elongation shall be as given in Table and Table JB.l When the shape of hot extruded section is not appropriate to take No 1A test piece, No.5 test piece may be taken In this case, the specifications in Table shall be replaced as follows : replace ~18 % by ~29 %, ~22 % by ~35 % for SM400A, SM400B and SM400C; replace ~17 % by ~27 %, ~21 % by ~33 % for SM490A, SM490B and SM490C; replace ~15 % by ~24 %, ~19 % by ~30 % for SM490YA, SM490YB, SM520B andSM520C JC.5.3 Charpy absorbed energy The hot extruded section of thickness over 12 mm given in Table shall be tested in accordance with 10.2, and the Charpy absorbed energy shall be as given in Table The test piece shall be taken in the direction of extrusion In this case, the value of Charpy absorption energy shall be taken from the mean of three test pieces and shall be judged by 9.6 of JIS G 0404 JC.6 Shape, dimensions and tolerances The shape of hot extruded sections shall be as specified by the purchaser When a specific shape cannot be formed, the purchaser shall specify changes of shape by agreement between the purchaser and the manufacturer NOTE: Hot extruded sections are used mainly as components specified in designing documents, based on technical standards such as standard specifications for building operations and common specifications for port construction work The tolerances on dimensions of hot extruded sections shall be as given in Table JC.2 PROTECTED BY COPYRIGHT 17 G 3106: 2015 Table JC.2 Tolerances on shape and dimensions Unit: mm Side, height and thickness Division < 50 2: 50 < 100 2: 100 < 200 2:200 :::;7m Tolerance ±1.5 ±2.0 ±3.0 ±4.0 Length +40 >7m For the plus side tolerance, add mm to the plus side tolerance for each increment of m or its fraction in length The minus side tolerance shall be Omm :::;100 mm in maximum :::;1.6 Squareness side length >100 mm in maximum :::;3.0 side length :::;0.5 % of length a) Bendability The tolerances may be moved to the plus side or minus side in the same range as the total tolerance range specified in Table JC.2 upon agreement between the purchaser and the manufacturer When the tolerance is moved to the plus side, the lower limits shall not be above zero, and, when it is moved to the minus side, the upper limits shall not be below zero Note a) Applicable to vertical and horizontal bending JC.7 Appearance The appearance of hot extruded sections shall be in accordance with clause of JIS G 3192 JC.B Inspection The inspection of hot extruded sections shall be in accordance with clause 11 JC.9 Reinspection The reinspection of hot extruded sections shall be In accordance with a) and b) of clause 12 JC.I0 Marking The marking of hot extruded sections shall be in accordance with clause 13 JC.ll Report The report of hot extruded sections shall be in accordance with clause 14 PROTECTED BY COPYRIGHT 18 G 3106 : 2015 Bibliography JIS G 0801 Ultrasonic testing ofsteel pIa tes for pressure vessels JIS G 0901 Classifica tion of structural rolled steel pIa te and wide 11a t for building by ultrasonic test PROTECTED BY COPYRIGHT Annex JD (informative) Comparison table between JIS and corresponding International Standards JIS G 3106 : 2015 Rolled steels foI' welded stI'uctUI'e (I) Requirements in JIS "'d o No and title of clause t.:rj Scope ~ o ~ t.:rj ~ U to ~ o Content (II) International Standard number ISO 630-1 : 2011 StI'uctw'al steels - PaI't : GeneI'al technical deliveIY conditions foI' hot-I'olled pI'oducts ISO 630-2 : 2011 StI'uctuI'al steels - Pad : Technical deliveIY conditions foI' stI'uctuI'al steels foI' geneI'al pUI'poses ISO 630-3 : 2012 StI'uctuI'al steels - PaI't 3: Technical deliveI'Y conditions foI' fine-gI'ain stI'uctuI'al steels (III) Requirements in International Standard (IV) Classification and details of technical deviation between JIS and the International Standard by clause No of clause Classifica tion by clause Detail of technical deviation Content Steel plates and sheets, steel strips in coil, sections and flats ISO 630-3 Steel plates, wide strips in coil, wide flats, bars, sections and profiles Alteration JIS excludes bars SM400A, B, C SM490A, B, C SM490YA, YB SM520C SM570 ISO 630-3 Characteristics of each grade and quality class SG245, SG290, SG325, SG345, SG365, SG415, SG460 Alteration Steel grade represents tensile strength in JIS while it represents yield point in o (V) Justification for the technical deviation and fu ture measures Other JIS specifies bars "'d sa """" o :::q ~ Normative references Classification, symbols and applicable thicknesses ISO o C,iJ I ' o OJ ~ o I ' I ' 01\.0 c;1t:-:l C;J ~ (I) Requirements in JIS No and title of clause Content (II) International Standard number (III) Requirements in International Standard No of clause 6.3 Five elements (C, Si, Mn, P, S) are specified Alloy elements can be added Elements specified shall be reported whenever added or not added Alteration ISO conforms to JIS in five elements Heat treatment and symbol of heat treatment Normalizing, quenching and tempering, tempering, thermo-mechanical control process and the like are specified ISO 630-3 6.2 Heat treatment such as as-rolled, normalizing and thermo-mechanical control process is specified Alteration Provisions regarding quenching and tempering are specified in ISO 630-4 Carbon equivalent and weld-crack sensitivity composition Carbon equivalent (Ceq) or weld -crack sensitivity composition (PCM) are specified ISO 630-1 ISO 630-3 6.3 6.3.3 q and PCM are specified The formula for q is slightly different from that in JIS a Addition IIW formula for q is used in ISO, but JIS uses a unique formula Mechanical properties Mechanical properties ISO 630-3 Inspection and test Alteration ~ t:rj o ~ t:rj U o ~ """" o ~ Detail of technical deviation ISO 630-3 o ~ Classifica tion by clause Five elements (C, Si, Mn, P, S) are specified Alloy elements can be added as necessary The content of alloy elements added needs to be reported "'d o Content Chemical composition ~ to (IV) Classification and details of technical deviation between JIS and the International Standard by clause ~ a 6.4 a - (V) Justification for the technical deviation and fu ture measures Most specifications in JIS have been covered in ISO A provision regarding PCM is adopted by ISO based on a proposal from Japan - o m t:-:l o ~ Of o (II) International Standard number (III) Requirements in International Standard (IV) Classification and details of technical deviation between JIS and the International Standard by clause No of clause Content Classifica tion by clause Detail of technical deviation 7.1 Yield point or proof stress, tensile strength and elongation ISO 630-3 6.4.1 Yield sterength (yield point or proof stress), tensile strength and elongation are specified Alteration Technically, the same contents are specified 7.2 Charpy absorbed energy Grade A : not specified Grade B : at least 27 J at °C Grade C : at least 47 J at °C SM570 : at least 47 J at -5°C ISO 630-1 ISO 630-3 4.2 6.4.2 Grade A : not specified Grade B : at least 27 J at 20°C Grade C : at least 27 J at °C Grade D : at least 27 J at -20°C Alteration JIS and ISO use slightly different specified values of temperature and Charpy absorbed energy Shape, dimensions, mass and tolerances JIS G 3192, JIS G 3193, JIS G 3194 are cited ISO 630-1 6.7 Specified by citing ISO Alternatively, other relevant standards like JIS may be used Addition Corresponding JIS is addressed in Annex A Appearance For appearance, JIS G 3192, JIS G 3193, and JIS G 3194 are cited ISO 630-1 6.5 As specified in ISO 7788, etc Alteration JIS does not accept the local insufficiency in plate thickness caused by removal of surface flaws, while ISO does (I) Requirements in JIS No and title of clause Mechanical properties (concluded) "'d ~ o ~ t.:rj o ~ t.:rj U to ~ o o "'d sa """" o :::q ~ Content (V) Justification for the technical deviation and fu ture measures The requirements have become similar between JIS and ISO, because of proposal by Japan Difference in commercial practices o C,iJ I ' o OJ ~ o I '~ 011 ' ... .lik~_thQ~_~ ~pg~ifiE}_