1、9 New From API API Publication 939-B, Repair and Remediation Strategies for Equipment Operating in Wet H2S Service This report summarizes the experimental methods and findings of a research program entitled Repair and Remediation Strategies for Equipment Operating in Wet H2S Service, conducted by th
2、e Materials Properties Council, Inc. (MPC). The program was jointly funded by MPC and the API Committee on Refinery Equipment. The overall goal of this project was to provide guidelines for effective repair procedures for use in remediation of equipment damaged in wet H2S service and to minimize the
3、 reoccurrence of cracking after inspection and/or repair. These included specific aspects related to: The use of temper bead as opposed to conventional weld repairs. The postweld heat treatment (PWHT) versus as-welded. Local thin areas in the base metal and grooves in the heat-affected zone (HAZ) wh
4、ich result from removal of cracks found by inspection. Influence of blend grinding on internal fillet-welded attachments. Evaluation of surface treatments. Serviceability of pre-existing wet H2S damage. Copies of API Publication 939-B may be purchased for $125.00 each. API members receive a 50% disc
5、ount on orders. To order, complete the order form and fax to (303) 397-2740 or call: (1-800) 854-7179 (Toll-free in the U.S. and Canada) or (303) 397-7956 (Local and International) June 2002 Downstream Segment Pages: 236 Price: $1 25.00 Product No. C939BO To download the online interactive version o
6、f the catalog on the Internet at our World Wide Web site - Go to: http:llwww.api.orglcatl Repair and Remediation Strategies for Equipment Operating in Wet H2S Service API PUBLICATION 939-B JUNE 2002 American Petroleum Institute Helping You Get nie Job Done Right? Repair and Remediation Strategies fo
7、r Equipment Operating in Wet H2S Service Downstream Segment API PUBLICATION 939-B JUNE 2002 American Petroleum Institute Helping You Get The Job Done Right.“ SPECIAL NOTES API publications necessarily address problems of a general nature. With respect to partic- ular circumstances, local, state, and
8、 federal laws and regulations should be reviewed. API is not undertaking to meet the duties of employers, manufacturers, or suppliers to warn and properly train and equip their employees, and others exposed, concerning health and safety risks and precautions, nor undertaking their obligations under
9、local, state, or fed- eral laws. Information Concerning safety and health risks and proper precautions with respect to par- ticular materials and conditions should be obtained from the employer, the manufacturer or supplier of that material, or the material safety data sheet. Nothing contained in an
10、y API publication is to be construed as granting any right, by implication or otherwise, for the manufacture, sale, or use of any method, apparatus, or prod- uct covered by letters patent. Neither should anything contained in the publication be con- strued as insuring anyone against liability for in
11、fringement of letters patent. Questions concerning the interpretation of the content of this publication or comments and questions concerning the procedures under which this publication was developed should be directed in writing to the director, Standards Department, American Petroleum Institute, 1
12、220 L Street, N.W., Washington, D.C. 20005, standardsapi.org. Requests for permission to reproduce or translate all or any part of the material published herein should also be addressed to the general manager. API standards are published to facilitate the broad availability of proven, sound engineer
13、- ing and operating practices. These standards are not intended to obviate the need for apply- ing sound engineering judgment regarding when and where these standards should be utilized. The formulation and publication of API standards is not intended in any way to inhibit anyone from using any othe
14、r practices. Any manufacturer marking equipment or materials in conformance with the marking requirements of an API standard is solely responsible for complying with all the applicable requirements of that standard. API does not represent, warrant, or guarantee that such prod- ucts do in fact confor
15、m to the applicable API standard. All rights reserved. No part of this work may be reproduced, stored in a retrieval system, or transmitted by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission from the publishel: Contact the Publishel; API Pub
16、lishing Services, 1220 L Street, N. W, Washington, D.C. 20005. Copyright O 22 American Petroleum institute 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 data contained in them; however, the Institut
17、e 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 regulation with which this publication may conflict.
18、 Suggested revisions are invited and should be submitted to the director, Standards Department, American Petroleum Institute, 1220 L Street, N.W., Washington, D.C. 20005, standards api.org . CONTENTS Page 1 EXECUTIVESUMMARY . 1 2 REJTRENCES 2 2.1 Standards. Codes. Publications. and Specifications .
19、2 2.2 Other References 2 3 ACRONYMS 3 4 INTRODUCTION 3 4.1 Background 3 4.2 Goal 3 4.3 Technical Approach 4 4.4 Terminology 4 5 EXPERIMENTALPROCEDURES 5 5.1 Materials Evaluated 6 5.2 Test Panel Configurations . 6 5.3 Experimental Overview 18 6 RESULTS AND DISCUSSION . 22 6.1 Materials Selection 22 6
20、.2 Postweld Heat Treatment . 23 6.3 Temper Bead Welding . 25 6.4 Blend Grindinfloe Dressings 25 6.5 Local Thin AreadGrooves 26 6.6 StripLining . 29 6.7 Arc StrikesLow Heat Input Welds . 30 6.8 Pre-existing Sohic 32 APPENDIX A EXPOSURE 1 DETAILED CRACKING RESULTS 37 APPENDIX B EXPOSURE 2 DETAILED CRA
21、CKING RESULTS . 105 APPENDIX C EXPOSURE 3 DETAILED CRACKING RESULTS . 175 Figures 1 2 3 4 5 6 7 8 9 10 11 12 HIC Damage Evaluation Formulas Given in NACE TM0284 . 6 Large-scale Pressure Vessel Used for this Study (PN-3040-1) 8 Schematic of the Large-scale Pressure Vessel Detailing the Materials Used
22、 . 9 Schematic of the Exposure 1 Test Panel Detailing the Variables Evaluated . 10 Structure of InterCorr 2289 CS . Magnification 200 x (PN 4464-6) . 11 Structure of InterCorr 3201 HRS . Magnification 200 x (PN 4464.7) 11 Structure of InterCorr 4475 . Magnification 200 x (PN 4464-5) 11 Location Codi
23、ng Used to Measure and Present the Detailed Cracking Data 12 Microhardness Survey Results from the Gnnd.out, Conventional Weld Repair Evaluated in Exposure 1 Test Panel 13 Microhardness Survey Results from the Grind.out, Temper Bead Weld Repair Evaluated in the Exposure 1 Test Panel . 13 Microhardne
24、ss Survey Results from Both Conventional and Temper Bead Attachment Welding Evaluated in the Exposure 1 Test Panel . 14 Schematic of the Exposure 2 Test Panel Detailing the Variables Evaluated . 15 V Page 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 Structure of InterCorr
25、2280 CS. Magnification 200 x (PN 4464-4) . 16 Microhardness Survey Results from the Conventional Full Penetration Weld without PWHT . 16 Microhardness Survey Results from the Conventional Full Penetration Weld with PWHT . 17 Microhardness Survey Results from the Grind-out, Conventional Weld Repair w
26、ith PWHT . 17 Microhardness Survey Results from the Grind-out, Temper Bead Weld Repair without PWHT 18 LTNGroove Profiles Evaluated in the Exposure 2 Test Panel. . 19 Schematic of the Exposure 3 Test Panel Detailing the Variables Evaluated . 20 Structure of InterCorr 2099 LSCS. Magnification 200 x (
27、PN 4464-3). 21 Structure of InterCorr 3247 HRS. Magnification 200 x (PN 4464-2). . 21 Structure of InterCorr 3250 TMCP Steel. Magnification 200 x (PN4464-1) 21 Facility Utilized to Produce the Pre-existing SOHIC in Two of the Exposure 3 Quarter Panels . 21 Comparison of the Base Metal Cracking Sever
28、ity Obtained in the 2289-A CS Pre-exposed to the NACE Standard TM0284, Solution B Versus the Subsequent Exposure in the Test Vessel to NACE TMO177, SolutionA 23 Comparison of Base Metal CLR Obtained in the 3201-B HRS, 4745-C CS and 2289-D CS Pre-exposed to the NACE Standard TM0177, Solution A Versus
29、 Subsequent Exposure in the Test Vessel to the Same Solution. . 23 Comparison of Base Metal CTR Obtained in the 3201-B HRS, 4745-C CS and 2289-D CS Pre-exposed to the NACE Standard TM0177, Solution A Versus Subsequent Exposure in the Test Vessel to the Same Solution. . 24 Cracking Severity of the CS
30、, LSCS, HRS and TMCP Steel Experienced in Exposure 3. Note the Decrease in Cracking Susceptibility with Increased Steel Cleanliness. 24 Schematic Explaining the Potential Benefit of Steels which Possess Higher CLR to CTR Ratios 24 Reduction in the Occurrence of SSC Toe Cracks with PWHT in the Attach
31、 Welds Evaluated in Exposure 3. 26 Number of Cracks Observed in the Conventional and Temper Bead Attachment Welds Illustrating the Slight Increase in the Occurrence of Cracking with the Temper Bead Technique 27 Average Crack Thickness in the Weld Area of the Conventional and Temper Bead Attachment W
32、elds . 27 Number of Cracks in the Weld Area between the Grind-out, Conventional Repair with PWHT and the Grind-out, Temper Bead Repair without PWHT. . 28 Total Crack Thickness in the Weld Area between the Grind-out, Conventional Repair with PWHT and the Grind-out, Temper BeadRepairwithoutP WHT 28 To
33、e Cracks Observed in the Blend Group Attachments on the 3201-B HRS. InterCorr 3201-22B, Magnification 50 x (PN 4465-3). . 29 Number of Fillet Welds with Toe Cracks Observed between the As-welded and Blend Ground Weld Toes . 29 SOHIC Extension from the Bottom of the Deep Toe Dressing on the LCSC Atta
34、chment Weld Evaluated in Exposure 3 (PN 4478-1) . 30 vi Page 37 38 39 40 41 42 43 44 Tables 1 Schematic of the Hydrogen Concentration Gradients Produced on a Toe Crack Observed in the Strip Lining Attachment Weld on the 2280-A CS Quarter Panel. InterCorr 2280-19, Magnification 50 x (PN 4466- 1). 3 1
35、 Toe Crack Observed in the Strip Lining Attachment Weld on the 3201-B HRS Quarter Panel. InterCorr 3201-32, Cracking at the Arc Strike on the LSCS. InterCorr 2099-9, Cracking at the Arc Strike on the TMCP Steel. InterCorr 3250-37, SOHIC Extension from the Base of the EDM Notch Observed on the LSCS i
36、n Exposure 3. InterCorr 2099-13, SOHIC Extension from the Base of the EDM Notch Observed on the HRS in Exposure 3. InterCorr 3247-20, Magnification 50 x (PN 4465-2). 35 SOHIC in the Base Metal of the LSCS, which Developed in the Absence of an Artificial Crack Initiator. InterCorr 2099-13, Magnificat
37、ion 50 x (PN 4465-6). 35 Full Wall Section of the Vessel Wall and the Remaining Ligament of an LTA . 3 1 Magnification 50 x (PN 4466-2). 32 Magnification 50 x (PN 4465-5). 33 Magnification 50 x (PN 4465-4). 33 Magnification 50 x (PN 4465-7). 34 MatenalsEvaluated 7 vi i Repair and Remediation Strateg
38、ies for Equipment Operating in Wet H2S Service 1 Executive Summary This report summarizes the experimental methods and findings of a research project titled Repair and Remediation Strategies for Equipment Operating in Wet H2S Service con- ducted by the Materials Properties Council, Inc. (MPC). The p
39、roject was jointly funded by MPC and the MI Committee on Refinery Equipment. The overall goal was to provide guidelines for effective repair procedures for use in remediation of equipment dam- aged in wet H2S service and to minimize the reoccurrence of cracking after inspection and/or repair. These
40、included spe- cific aspects related to: a. The use of temper bead as opposed to conventional weld repairs. b. The postweld heat treatment (PWHT) versus as-welded. c. Local thin areas in the base metal and grooves in the heat- affected zone (HAZ) which result from removal of cracks found by inspectio
41、n. d. Influence of blend grinding on internal fillet-welded attachments. e. Evaluation of surface treatments. f. Serviceability of pre-existing wet H2S damage. To accomplish these goals, a series of large-scale exposure tests were conducted with steel test panels, containing various repair and remed
42、iation variables, welded into the body of a large-scale fabricated steel vessel filled with a pressurized H2S containing solution prepared in accordance with NACE Standard Th40177, Solution A. Experiments were performed using test panels comprised of conventional, low sulfur con- ventional, hydrogen
43、-induced cracking (HIC) resistant and advanced thermo-mechanically controlled processed steels per the ASTM A 516-70, A 285-C and A 841 specifications. One of the most significant findings of the project was the impact of PWHT on reducing the number of toe cracks on both full penetration and attachm
44、ent welds. It was demon- strated that the impact of PWHT was the result of: 1. The reduction in hardness observed in the weld area. 2. The reduction in the tensile residual stresses in the weldment. These findings were supported by two series of experi- ments. One of the experiments compared the per
45、formance of as-welded versus PWHT attachments. A large number of toe cracks were produced on the as-welded attachments to conventional and low-sulfur conventional A 516-70 and no toe cracks were observed on the PWHT attachments. The difference in performance related most heavily to the range in hard
46、ness between the two techniques. In another experiment, as-welded and PWHT full penetration welds were fabricated in one of the test panels. Both the as- 1 welded and PWHT full penetration welds possessed low hardnesses with respect to sulfide stress cracking (SSC) susceptibility; however, the as-we
47、lded, full penetration weldments still produced toe cracks despite the low hard- ness levels. Hence, the benefit of PWHT in this case most likely related to the reduction in tensile residual stress across the weldments combined with the reduced hardness as a result of PWHT. Another important finding
48、 was the similarity in perfor- mance between conventional weld repairs with PWHT and temper bead weld repairs without PWHT. If repair welds are to be PWHT, then the weld repair would be made using a conventional procedure; however, if the repair welds are not to be subjected to a PWHT then the use o
49、f a temper bead technique might be chosen. In this project, the number of cracks observed in the weld area between the two procedures was nearly equivalent. Comparison of the total crack thick- ness in the weld area for both techniques also revealed consis- tency in behavior between the two techniques. No benefit was derived from the use of blend grinding. In general, blend ground fillet attachment welds produced a greater number of toe cracks than non-treated fillet attach- ments. Deep toe dressings were also evaluated at fillet attach- ments and along full penetration welds. These resul
