1、STP-PT-058TEMPER BEAD QUALIFICATION HARDNESS ACCEPTANCE CRITERIASTP-PT-058 TEMPER BEAD QUALIFICATION HARDNESS ACCEPTANCE CRITERIA Prepared by: David Abson, Adrienne Barnes and Sayee Raghunathan TWI Ltd Steve Jones Rolls-Royce plc Date of Issuance: June 28, 2013 This document was prepared as an accou
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9、ue, New York, NY 10016-5990 ISBN No. 978-0-7918-6908-6 Copyright 2013 by ASME Standards Technology, LLC All Rights Reserved Temper Bead Qualification Hardness Acceptance Criteria STP-PT-058 iii TABLE OF CONTENTS Foreword . vi Executive Summary . vii PART I . 1 1 INTRODUCTION . 2 2 OVERVIEW OF CONTRO
10、LLED DEPOSITION REPAIR STRATEGIES 4 3 REPAIR USING NEAR-MATCHING WELD METAL 5 4 REPAIR USING NI-BASE WELD METAL 10 5 HAZ HARDNESS . 11 6 RESIDUAL STRESSES 18 7 REPAIR OF SERVICE AND AGED MATERIAL 19 8 CODES AND STANDARDS 20 8.1 Fabrication Specifications, Codes and Standards 20 8.1.1 American Codes
11、and Standards 20 8.1.2 European Codes and Standards 21 9 VARIABLES AFFECTING TEMPER BEAD 22 10 SUMMARY AND CONCLUSIONS 23 References Part I . 24 PART II 29 1 INTRODUCTION . 30 2 EXPERIMENTAL DETAILS . 31 2.1 Parent Steels 31 2.2 Welding Consumables . 31 2.3 Welding Details . 31 2.4 Metallographic Pr
12、eparation and Examination . 33 2.5 Hardness Testing . 33 2.6 Charpy Impact Testing 34 3 RESULTS 36 3.1 Parent Steels 36 3.2 Welding . 38 3.3 Weld Metal Chemical Composition 38 3.4 Metallographic Observations 39 3.5 Hardness Data 49 3.6 Charpy Impact Data . 54 3.7 Investigation of the relationship be
13、tween HAZ hardness and HAZ Charpy Toughness . 58 4 DISCUSSION 62 5 CONCLUSIONS . 64 STP-PT-058 Temper Bead Qualification Hardness Acceptance Criteria iv 6 RECOMMENDATIONS . 65 References Part II . 66 Appendix A “Poor” and “Optimum” welding procedures . 67 Appendix B Hardness Test Records 73 Appendix
14、 C Charpy Test Data . 89 Acknowledgments . 97 Abbreviations and Acronyms . 98 LIST OF TABLES Table 1HAZ Hardness Values Reported in the Literature for Controlled Deposition Repairs C-Mn steel . 12 Table 2HAZ Hardness Values Reported in the Literature for Controlled Deposition Repairs in C-Mn-Ni-Cr-M
15、o and C-Mn-Ni-Cr-Mo Steels 13 Table 3HAZ Hardness Values Reported in the Literature for Controlled Deposition Repairs 0.5%Cr-0.5%Mo-0.25%V Steel 14 Table 4HAZ Hardness Values Reported in the Literature for Controlled Deposition Repairs 1.25%Cr-0.5%Mo Steel 14 Table 5HAZ Hardness Values Reported in t
16、he Literature for Controlled Deposition Repairs 2.25%Cr-1%Mo Steel . 16 Table 6HAZ Hardness Values Reported in the Literature for Controlled Deposition Repairs 9%Cr-1%Mo Steel 17 Table 7Initial Welded Panels for Procedure Development . 32 Table 8Chemical Composition of Parent Steels (determined by T
17、WI) 37 Table 9Welded Panels for Subsequent Study . 38 Table 10Chem ical Composition of Weld Metals 38 Table 11Ha rdness Data for Weldments in P4 Parent Steels . 50 Table 12Ha rdness Data for Weldments in P5A Parent Steels 52 Table 13Parent Steel Charpy Toughness Data 56 Table 14HA Z Charpy Toughness
18、 Data Compared with the HAZ Charpy Toughness Data for P5 (Lower CE) Parent Steel Supplied by Rolls-Royce . 57 Table 15HAZ Charpy Toughness and Hardness Data 1-Layer . 60 Table 16HAZ Charpy Toughness and Hardness Data 4-Layer . 61 LIST OF FIGURES Figure 1Schematic Diagram Illustrating the Relationshi
19、p between the Fe-C Phase Diagram and the Different Regions of the HAZ 1 . 2 Figure 2Schematic Representation of Two-Layer Refinement Parameters 5 Figure 3Ill ustration of the Use of Shims, Tack Welded from the Inside of the Repair Cavity, to Avoid a Large Untempered HAZ at the Surface . 6 Temper Bea
20、d Qualification Hardness Acceptance Criteria STP-PT-058 v Figure 4Illustration of the Early Stages of a Small Patch Repair the Weld Beads Stop and Start on the Initial Peripheral Bead. 7 Figure 5Weld Metal and Parent Steel Hardness for Grade 91 Steel, as a Function of Larsen-Miller Parameter 24 . 8
21、Figure 6Schematic Representation of the Bead Arrangement for the Cascade Weld 32 Figure 7Diagram Showing the Intended Positions of Hardness Indentations in the 1-Layer and 4-Layer Sections . 34 Figure 8Completed Panels Showing the Cascade Weld and the Additional Weld Pad Added within the 4-Layer Reg
22、ion to Allow Charpy Specimens to be Machined with the Notch Lying in the HAZ . 35 Figure 9Photomicrographs of Weld Transverse Sections from Weld TW1 Reflecting the “Optimum“ Procedure in P5 Steel 39 Figure 10Photomicrographs of Weld Transverse Sections from Weld TW6 Reflecting the “Poor“ Procedure i
23、n a P4 Steel . 40 Figure 11Photom icrographs Showing a Coarse-Grain Region in the 4-Layer Region of TW 3 41 Figure 12Photom icrographs Showing a Fine-Grain Region in the 4-Layer Region of TW 3 42 Figure 13Photomicrographs Showing a Fusion Boundary Region in 1-Layer Region of TW 6 44 Figure 14Grain S
24、ize Measurements for Weldments in the Lower IIW CE P4 Steel 45 Figure 15Grain Size Measurements for Weldments in the Higher IIW CE P4 Steel . 46 Figure 16Grai n Size Measurements for Weldments in the Lower IIW CE P5 Steel 47 Figure 17Grain Size Measurements for Weldments in the Higher IIW CE P5 Stee
25、l . 48 Figure 18Pare nt Steel Charpy Toughness P4 . 54 Figure 19Pare nt Steel Charpy Toughness P5 . 55 Figure 20Mea n Vickers Hardness vs. Absorbed Energy at -12 C 1-Layer 58 Figure 21Maximum Vickers Hardness vs. Absorbed Energy at -12 C 1-Layer 58 Figure 22Mean Vickers Hardness vs. Absorbed Energy
26、at -12 C 4-Layer 59 Figure 23Maximum Vickers Hardness vs. Absorbed Energy at -12 C 4-Layer 59 Figure 24Hardness versus Charpy 30 5J Temperature for Course-Grained HAZ Regions, for 5KJ/mm Submerged Arc Welds . 63 STP-PT-058 Temper Bead Qualification Hardness Acceptance Criteria vi FOREWORD Part I Rev
27、iew of Controlled Deposition Repair Literature Where repairs to steel fabrications are required, but where a subsequent Post-Weld Heat Treatment (PWHT), although desirable, is impractical, as a result of constraints of cost, time or feasibility, it may be appropriate to carry out a controlled deposi
28、tion repair, which generates a fine-grained Heat-Affected Zone (HAZ), by judicious choice of welding parameters and welding procedure. For some applications, the resulting maximum HAZ hardness is of interest and potential concern. Published literature on controlled deposition repair welding in C-Mn
29、and low alloy steels by different welding processes has been reviewed, and the resulting maximum HAZ hardness values have been tabulated. Part II Experimental Program Repair welding without a subsequent PWHT is allowed in various ASME fabrication codes, but is not currently allowed for P4 and P5A st
30、eels. The present project was undertaken to determine reasonable upper limits for the HAZ hardness produced during controlled deposition Shielded Metal Arc Welding (SMAW) repairs in these two steels, and also to investigate whether there is any correlation between HAZ hardness and HAZ impact toughne
31、ss. The project was supported by ASME Pressure Technology Codes and Standards (PTCS) and was carried out by TWI Ltd, in collaboration with Rolls-Royce plc, who supplied the parent steels and welding consumables, and performed all of the welding on the project. About ASME Established in 1880, the Ame
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33、safety, and provides lifelong learning and technical exchange opportunities benefiting the engineering and technology community. Visit www.asme.org for more information. The ASME Standards Technology, LLC (ASME ST-LLC) is a not-for-profit Limited Liability Company, with ASME as the sole member, form
34、ed in 2004 to carry out work related to newly commercialized technology. The ASME ST-LLC mission includes meeting the needs of industry and government by providing new standards-related products and services, which advance the application of emerging and newly commercialized science and technology a
35、nd providing the research and technology development needed to establish and maintain the technical relevance of codes and standards. Visit www.stllc.asme.org for more information. Temper Bead Qualification Hardness Acceptance Criteria STP-PT-058 vii EXECUTIVE SUMMARY Part I Review of Controlled Dep
36、osition Repair Literature Background For fabrications where the need for a welded repair has been identified, but for which a Post-Weld Heat Treatment (PWHT) would be impractical or expensive, it is possible to affect a repair by using a procedure which is intended to give rise to significant refine
37、ment and tempering of the Heat-Affected Zone (HAZ) microstructure. Various approaches to such repair, in terms of selection of welding parameters, welding process and consumables, have been explored by numerous organizations over several decades. Published investigations and the provision for contro
38、lled deposition repair in various standards are considered in this review. Objective To compile a review of the literature relating to controlled deposition and temper bead repair welding. Work Carried Out Publications from a wide range of sources have been reviewed, and relevant information, includ
39、ing values of maximum HAZ hardness, has been extracted, and incorporated into this review. The current requirements of key codes and standards have also been addressed. TWIs Weldasearch database has been used to assist in locating relevant sources of information. Part II Experimental Program Backgro
40、und In appropriate circumstances, a controlled deposition repair may be carried out without a subsequent PWHT. The approach is well established, and such repairs are allowed in various ASME fabrication codes, generally employing SMAW. The present project was carried out on 1.25%Cr-0.5%Mo (P-No 4 Gr-
41、No 1) and 2.25%Cr-1%Mo (P-No 5A Gr-No 1) steels. It is intended to establish, for controlled deposition repair welds in these steels, the likely maximum HAZ hardness values, and to investigate whether there is a correlation between HAZ microstructure, hardness and Charpy toughness. To this end, pane
42、ls have been welded in the 3G position, and the HAZ ASTM grain size, the hardness, and also the HAZ Charpy toughness, have been determined. The project was carried out in collaboration with Rolls-Royce plc, who supplied the parent steels and welding consumables, and performed all of the welding on t
43、he project. Objectives To determine maximum HAZ Vickers hardness values for controlled deposition (“temper bead”) repair welds in 1.25%Cr-0.5%Mo and 2.25%Cr-1%Mo steels for incorporation into ASME codes. To investigate any possible correlation between HAZ grain size, hardness and Charpy toughness. W
44、ork Carried Out 1.25%Cr-0.5%Mo (P-No 4 Gr-No 1) and 2.25%Cr-1%Mo (P-No 5A Gr-No 1) parent steels were selected with the aim of obtaining a steel of each group with an IIW CE towards the top of the likely range, and also a steel with a lower value of IIW CE. Controlled deposition welds were deposited
45、 in the 3G position as “cascade” welds, so that sections could be taken through 1, 2, 3 and 4-layer deposits for subsequent study. The thickness of the 4-layer region was extended locally so that STP-PT-058 Temper Bead Qualification Hardness Acceptance Criteria viii Charpy specimens could be extract
46、ed with the notch located in the HAZ below the controlled deposition deposit. A procedure with 50% bead overlap, and also one with 25% overlap (intended to reflect incorrect application of a controlled deposition procedure), were employed. The metallographic sections were polished and etched, and we
47、re examined under an optical microscope at a range of magnifications, so that ASTM grain sizes of the HAZ could be determined in selected locations. The Vickers hardness was also determined in approximately the same locations. Charpy specimens were machined from each of the parent materials, and wer
48、e tested to give transition curves. HAZ Charpy toughness was subsequently measured in triplicate at specific temperatures. Conclusions (a) The grain size in the coarse-grain regions was generally in the range ASTM 4 to ASTM 7, while that in the fine-grain regions generally ranged from ASTM 8 to ASTM
49、 14. (b) For both the “optimum” and “poor” procedures the grain size in the fine grain regions was finer for the 4-layer section than for the 1-layer section, indicating that the deposition of the later layers affected some HAZ grain refinement (c) For the P-No 5A deposits and also for the 1-layer P-No 4 transverse sections, the HAZ hardness was marginally higher for the “poor” procedure. For the P-No 4 panels, the HAZ hardness was marginally higher for the “optimum” procedure in the 4-layer trans
