1、Recommended Practice for Preproduction Qualification for Steel Plates for Offshore StructuresAPI RECOMMENDED PRACTICE 2ZFOURTH EDITION, SEPTEMBER 2005REAFFIRMED, JUNE 2015Recommended Practice for Preproduction Qualification for Steel Plates for Offshore StructuresUpstream SegmentAPI RECOMMENDED PRAC
2、TICE 2ZFOURTH EDITION, SEPTEMBER 2005REAFFIRMED, JUNE 2015SPECIAL NOTESAPI publications necessarily address problems of a general nature. With respect to particular circumstances, local, state, and federal laws and regulations should be reviewed.Neither API nor any of APIs employees, subcontractors,
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10、 InstituteFOREWORDThis Recommended Practice is under jurisdiction of the API Subcommittee on Standardiza-tion of Offshore Structures.The purpose of this recommended practice is to provide recommendations for the pre-pro-duction qualification of steelmaking procedures for steel plates for use in weld
11、ed offshore structures.This standard shall become effective on the date printed on the cover but may be used volun-tarily from the date of distribution. API publications may be used by anyone desiring to do so. Every effort has been made by the Institute to assure the accuracy and reliability of the
12、 data contained in them; however, the Institute makes no representation, warranty, or guarantee in connection with this publication and hereby expressly disclaims any liability or responsibility for loss or damage resulting from its use or for the violation of any federal, state, or municipal regula
13、tion with which this publication may conflict.Suggested revisions are invited and should be submitted to the director of the Exploration and Production Department, American Petroleum Institute, 1220 L Street, N.W., Washing-ton, D.C. 20005.Nothing contained in any API publication is to be construed a
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17、sed to the director.Generally, API standards are reviewed and revised, reaffirmed, or withdrawn at least every five years. A one-time extension of up to two years may be added to this review cycle. Status of the publication can be ascertained from the API Standards Department, telephone (202) 682-80
18、00. A catalog of API publications and materials is published annually and updated quarterly by API, 1220 L Street, N.W., Washington, D.C. 20005.Suggested revisions are invited and should be submitted to the Standards and Publications Department, API, 1220 L Street, NW, Washington, DC 20005, standard
19、sapi.org.iiiCONTENTSPage1 INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11.1 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11.2 Scope. . . . . . .
20、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11.3 General Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12 REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
21、 . . . . . . . . . . . . . . . . . . . . . . . . . . .23 QUALIFICATION FOR HAZ TOUGHNESS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24 DELAYED CRACKING TEST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .134.1 Purpose . . . . . . . . . . . .
22、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .134.2 Controlled Thermal Severity (CTS) Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .134.3 The Y-Groove Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
23、 . . . . . . . . . .134.4 Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .134.5 Commentary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .145 RE-QUALIFICATION . . . . . .
24、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14APPENDIX A SUGGESTIONS FOR ORDERING API RP 2Z PRE-PRODUCTION QUALIFICATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19Figures1 Single-bevel and K-
25、bevel Weld Preparations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32 Various Regions of a Single-pass, Bead-on-plate Weld . . . . . . . . . . . . . . . . . . . . . . .73a Eliminated, Altered and Unaltered Regoins of a Two-phase, Bead-on-plate Weld .83b Identification of Some Altere
26、d and Unaltered Regions . . . . . . . . . . . . . . . . . . . . . . .84a HAZ Regions in a Multi-pass Weld with One Plate Edge, Unbeveled . . . . . . . . . . .94b Unaltered Coarse-grain HAZ (CGHAZ) in a Multi-pass Weldwith one Plate Edge, Unbeveled . . . . . . . . . . . . . . . . . . . . . . . . . .
27、. . . . . . . . . . . . . 104c Inter critically and Sub Critically Reheated CGHAZ Regions(IRCG and SRCG, Respectively . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .114d Unaltered Subcritical HAZ (SCHAZ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28、. . .125a Sectioning the Weld Half of a HAZ CTOD Specimen . . . . . . . . . . . . . . . . . . . . . .165b Calculation of CG Region Sampled by the Fatigue Crack Tip . . . . . . . . . . . . . . . .176 Sectioning Both Halves of a HAZ CTOD Specimen toCalculate CG Region Percentage . . . . . . . . . . .
29、. . . . . . . . . . . . . . . . . . . . . . . . . . . 18Tables1 CTOD Testing Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42 Tolerances for Minor and Major Changes in Melting, Casting,and Processing Variables Other Than Chemistry . . . . . . . . .
30、 . . . . . . . . . . . . . . . . . 15v1Recommended Practice for PreproductionQualification for Steel Plates for Offshore Structures1 Introduction1.1 PURPOSEThe purpose of these recommendations is to provide the purchaser with information which can be used to minimize the amount of time and testing n
31、ecessary to prepare and certify fabrication welding procedures (and to assure that the steel to be supplied is inherently suitable for welding) with particular attention to fracture toughness and resistance to cracking of the heat affected zone. It is presupposed that welding procedures suitable for
32、 the demonstrated capabilities of the steel and intended service will be sepa-rately developed.1.1.1 The specific testing required shall be that described in either Section 3 or 4 or both, as specified in the purchase order.1.1.2 Demonstration of conformance to the recommendations of this practice q
33、ualifies a particular mill to produce steel manu-factured to the specific chemical composition range, melting practice, and processing practice for which conformance was estab-lished. The qualification is applicable to all orders for material produced under the conditions qualified.1.1.3 A significa
34、nt change in chemical composition or processing practice that could be detrimental to either weldability or toughness shall require either a separate full qualification (for major change) or an abbreviated re-qualification (for minor change), as described in Section 5.1.1.4 Prior qualification may b
35、e accepted for the fulfillment of the recommendations of this practice. Testing to a wider range of heat input, higher CTOD values, or lower test temperatures is encouraged, and shall be deemed to satisfy the minim recom-mendations of this Practice.1.2 SCOPEThis Recommended Practice covers requireme
36、nts for Preproduction qualification, by special welding and mechanical testing, of specific steelmaking and processing procedures for the manufacture of steel of a specified chemical composition range by a spe-cific steel producer. This is a Recommended Practice for material selection and qualificat
37、ion, but not for the performance of pro-duction weld joints. This Recommended Practice was developed in conjunction with, and is intended primarily for use with, API Specifications 2W and 2Y. However, it may be sued as a supplement to other material specification s (e.g., API Specification 2H) if so
38、 desired.1.3 GENERAL REQUIREMENTS1.3.1 Unless otherwise specified, the testing recommended by this practice need only include material from a single heat of steel produced to the specific range of chemical composition to be qualified.1.3.2 The plate processing, welding, and testing shall be conducte
39、d by or under the control of the steel producer, but shall be witnessed by a third party or a representative of a purchaser.1.3.3 The test results, together with a detailed description of the processing of the steel, shall be documented by the producer and a copy provided to the purchaser. It is not
40、 intended, however, that proprietary information be included in the documentation. It is intended that the steel producers “know-how“ shall remain confidential. It is necessary, however, that sufficient information be included in the documentation package so that a purchaser can confirm at a later d
41、ate that all essential procedures are being fol-lowed. At the very least, the manufacturers process shall be designated by a code number or designation sufficient to provide traceability of process variables.1.3.4 The chemical composition of the steel, as determined by heat analysis, shall conform t
42、o the requirements of the applicable industry standard under which it is to be produced. Within these typically broad limits, the steelmaker shall nominate the aim chemical composition and working range which define limiting essential variables for which the Preproduction qualification may be assume
43、d to remain valid.Tests conducted on any one heat shall qualify subsequent production heats described in Section 5.2 API RECOMMENDED PRACTICE 2Z1.3.5 Documentation shall include a complete characterization of the base metal properties of the steel tested, including the following:a. Complete chemical
44、 composition, listing the elements in section 5.2 and all additions.b. Tensile test results, including stress-strain curves to peak load.c. Charpy V-notch transition curves for absorbed energy, lateral expansion opposite the notch, and fracture appearance. Each transition curve shall consist of a mi
45、nimum of 12 specimens (at least 4 temperatures, sufficient to define the upper and lower shelf and 50% FATT). Samples for new qualifications to be mid-thickness with T-L orientation, at the following for locations:1. mother plate head, mid width2. mother plate head, plate edge3. mother plate tail, m
46、id width4. mother plate tail, plate edge.d. Drop-weight nil-ductility temperature.e. Hardness traverse.f. For new qualifications, results of centerline segregation control tests, to include macroetch of both slab and plate for concast, plate only for ingot cast steel.1.3.6 Any reference to a steel h
47、aving API RP 2Z qualification shall be accompanied by reference to the tested heat input range, CTOD test temperature, material strength or grade, and thickness.2 References2.1 The most recent editions of revisions of the following standards are referenced in this publication:ASTM1E 1290 Standard Te
48、st Method for Crack Tip Opening Displacement (CTOD) Fractural Toughness MeasurementSTP-995 Non-Linear Fracture Mechanics: Volume II Elastic Plastic FailureAWS2A 4.3 Determination of Diffusible HydrogenD.1.1 Structural Welding CodeSteelBS37448 Part 1: Method for determination of KIc, critical CTOD, a
49、nd critical J values of welds in metallic materials7448 Part 2: Method for determination of KIc, critical CTOD, and critical J values of welds in metallic materials7363 Methods for Controlled Thermal Severity (CTS) Test and Bead-on-Plate (BoP) Tests for WeldsJIS4Z 3158 Method of Y-Groove Weld Cracking Test3 Qualification for HAZ Toughness3.1 Each pre-qualification shall consist of preparation of three butt welds using test plates with either a K-bevel or single-bevel joint preparation (See Figure 1), subjection to agreement between purchaser and manufacturer. The weld shall be parallel
