1、Fabrication Considerations for Vanadium-Modified Cr-Mo Steel Heavy Wall Pressure VesselsAPI TECHNICAL REPORT 934-B FIRST EDITION, APRIL 2011Fabrication Considerations for Vanadium-Modified Cr-Mo Steel Heavy Wall Pressure VesselsDownstream SegmentAPI TECHNICAL REPORT 934-B FIRST EDITION, APRIL 2011Sp
2、ecial 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, consultants, committees, or other assignees make any warran
3、ty or representation, either express or implied, with respect to the accuracy, completeness, or usefulness of the information contained herein, or assume any liability or responsibility for any use, or the results of such use, of any information or process disclosed in this publication. Neither API
4、nor any of APIs employees, subcontractors, consultants, or other assignees represent that use of this publication would not infringe upon privately owned rights.API publications may be used by anyone desiring to do so. Every effort has been made by the Institute to assure the accuracy and reliabilit
5、y of the 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 authorities having jurisdic
6、tion with which this publication may conflict.API publications are published to facilitate the broad availability of proven, sound engineering and operating practices. These publications are not intended to obviate the need for applying sound engineering judgment regarding when and where these publi
7、cations should be utilized. The formulation and publication of API publications is not intended in any way to inhibit anyone from using any other practices.Any manufacturer marking equipment or materials in conformance with the marking requirements of an API standard is solely responsible for comply
8、ing with all the applicable requirements of that standard. API does not represent, warrant, or guarantee that such products do in fact conform to the applicable API standard.All rights reserved. No part of this work may be reproduced, translated, stored in a retrieval system, or transmitted by any m
9、eans, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission from the publisher. Contact the Publisher, API Publishing Services, 1220 L Street, NW, Washington, DC 20005.Copyright 2011 American Petroleum InstituteForewordNothing contained in any API publicatio
10、n is to be construed as granting any right, by implication or otherwise, for the manufacture, sale, or use of any method, apparatus, or product covered by letters patent. Neither should anything contained in the publication be construed as insuring anyone against liability for infringement of letter
11、s patent.This document was produced under API standardization procedures that ensure appropriate notification and participation in the developmental process and is designated as an API standard. Questions concerning the interpretation of the content of this publication or comments and questions conc
12、erning the procedures under which this publication was developed should be directed in writing to the Director of Standards, American Petroleum Institute, 1220 L Street, NW, Washington, DC 20005. Requests for permission to reproduce or translate all or any part of the material published herein shoul
13、d also be addressed to the director.Status of publications can be ascertained from the API Standards Department, telephone (202) 682-8000. A catalog of API publications and materials is published annually by API, 1220 L Street, NW, Washington, DC 20005.Suggested revisions are invited and should be s
14、ubmitted to the Standards Department, API, 1220 L Street, NW, Washington, DC 20005, standardsapi.org.iiiContentsPage1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Normative
15、 References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Definitions and Acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
16、 . . . 23.1 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23.2 Acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
17、. . . . . . . . . . . . . . . . . . . . . . . . . . 34 Design and Fabrication. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44.1 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
18、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44.2 Identified Fabrication Problems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44.3 Code References and Design Allowables . . . . . . . .
19、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84.4 Incorporation Into API 941 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104.5 Additional Characteristics . . . . . . . . . .
20、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114.6 Metallurgical Concerns During Fabrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114.7 Best Practices for Fabricating V-Modi
21、fied 21/4Cr-1Mo Vessels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 Assessment of Fabricators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185.1 Current Worldwide Fabrication Capability . . .
22、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185.2 Approving New Fabricators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18Annex A (informative) SAMPLE Fabrication Pl
23、an . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22Annex B (informative) Example of a Detailed Fabrication Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23Annex C (informative) Sample Fabrication Schedule . .
24、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28Figures1 Charpy V-Notch Toughness
25、 of Conventional and Vanadium-modified 21/4Cr-1Mo Deposited Weld Metal after DHT and ISR Heat Treatment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 Vanadium Content versus Creep Rupture of Cr-1Mo-V Steels . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
26、. . . . . 113 Typical Conventional and Vanadium-modified 21/44Cr-1Mo Weld Metal Hardness After Various Heat Treatments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 Diffusible Hydrogen Test Results for 21/4Cr-1M
27、o Weld Metal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 Charpy V-Notch Toughness of Vanadium-modified 21/4Cr-1Mo Deposited Weld Metal after ISR Using a Second Alternative Wire Flux Combination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15A.1
28、Sample Fabrication Plan. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22Tables1 Typical Properties of Materials of Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
29、 . . . 92 Toughness Properties of Vanadium-modified Sub-Arc Weld Metal as Function of Heat Treatment Condition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 Point System for Evaluating New Fabricators . . . . . . . . .
30、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19B.1 Example Construction Schedule. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23vIntroductionThis document is intended as a best practice guidelin
31、e to be used by fabricators, in conjunction with API 934-A, when constructing new heavy wall pressure vessels with vanadium-modified Cr-Mo steels intended for service in petroleum refining, petrochemical, or chemical facilities. These materials are primarily used in high temperature, high pressure s
32、ervices which contain hydrogen.The document provides typical practices to be followed during fabrication based upon experience and the knowledge gained from actual problems that have occurred during the fabrication of vanadium-modified Cr-Mo steels.BackgroundThe use of chrome-molybdenum steel vessel
33、s in hydrogen service can be traced back to the mid 1920s in Germany where they were used for reactors in high pressure hydrogenation plants. These vessels were fabricated from 2.25 % to 3.8 % chrome-molybdenum alloys operating in the pressure range of 28 to 70 MPa (4000 to 10,000 psi). 1These steel
34、s are now referred to as the “First Generation” technology and were in use until the mid 1960s. The steels have evolved with significant improvements in each generation that can be summarized as follows.Second Generation (Mid 1960s to 1970s) The birth of modern hydroprocessing reactors manufactured
35、from heavy wall 21/4Cr-1Mo alloys with improved toughness (54 Joules at 10 C 40 ft-lbs at 50 F), but with no particular temper embrittlement controls.Third Generation (1970s to 1980s) Added J-factor limit of 180 to control temper embrittlement and developed improved toughness to 54 Joules at 18 C (4
36、0 ft-lbs at 0 F). Also, began step cooling tests with varying criteria, and precautions against weld overlay disbondment.Fourth Generation (1980s to 1990s) Improved temper embrittlement control by lowering J-factor limit to 100 and achieving better results after step cooling. This generation also ha
37、d toughness improvements to 54 Joules at 32 C (40 ft-lbs at 25 F)Today “Fifth Generation” grades 2of conventional 2Cr-1Mo steels have a 54-Joule (40 ft-lb) transition temperature typically lower than 40 C (40 F), and even lower for conventional 3Cr-1Mo steels. Vanadium-modified Cr-Mo steels with 21/
38、4 % and 3 % Cr were introduced for service with higher strength levels and increased hydrogen attack resistance. These grades achieved a 54 Joule (40 ft-lb) transition temperature typically around 29 C (20 F). The vanadium-modified steels also offered enhanced creep rupture properties, lower temper
39、embrittlement susceptibility, and a much lower susceptibility to hydrogen disbonding of weld overlay compared with conventional Cr-Mo steels. As of 2009, over four hundred vanadium-modified reactors have been fabricated around the world with many more under construction. vi1Fabrication Consideration
40、s for Vanadium-Modified Cr-Mo SteelHeavy Wall Pressure Vessels1 ScopeThis best practice report complements API 934-A and specifies additional fabrication considerations that should be observed when constructing a new heavy wall pressure vessel using vanadium-modified Cr-Mo materials intended for hyd
41、rogen service at elevated temperature and pressure. It applies to vessels that are designed, fabricated, certified and documented in accordance with ASME Code Section VIII, Division 2, including Paragraph 3.4 of the ASME Code, Supplemental Requirements for Cr-Mo Steels and ASME Code Case 2151, as ap
42、plicable (or equivalent international codes). Nominal material chemistries covered by this report are the vanadium-modified steels including 21/4Cr-1Mo-1/4V, 3Cr-1Mo-1/4V-Ti-B, and 3Cr-1Mo-V-Cb-Ca steels. The interior surfaces of these vessels may have an austenitic stainless steel cladding or weld
43、overlay to provide additional corrosion resistance.2 Normative ReferencesThe following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including a
44、ny amendments) applies. API Recommended Practice 582, Welding Guidelines for the Chemical, Oil, and Gas IndustriesAPI Recommended Practice 934-A, Materials and Fabrication Requirements for 2 1/4Cr-1Mo t is time in hours (hr).3.1.8 maximum PWHT Specified heat treatment of test specimens used to simul
45、ate all fabrication heat treatments including austenitizing and tempering, all intermediate heat treatments above 482 C (900 F), the final PWHT, a PWHT cycle for possible shop repairs, and a minimum of one extra PWHT cycles for future use by the owner. NOTE To determine the equivalent time at one te
46、mperature (within the PWHT range), the Larson-Miller Parameter formula may be used; results to be agreed upon by purchaser and manufacturer.3.1.9 minimum PWHT Specified heat treatment of test specimens used to simulate the minimum heat treatment (austenitizing, tempering and one PWHT cycle, and ISR
47、above 482 C 900 F). NOTE To determine the equivalent time at one temperature (within the PWHT range), the Larson-Miller Parameter may be used; results to be agreed upon by purchaser and manufacturer.3.1.10 owner The firm or organization that will own and operate the pressure vessel.3.1.11 seller The
48、 successful bidder, the firm or organization receiving the purchase order to design and fabricate the pressure.3.1.12 step cooling heat treatment Specified heat treatment of test specimens used to simulate and accelerate embrittlement of test specimens for the purpose of evaluating the potential for
49、 temper embrittlement of alloy steels in high-temperature service.3.1.13 sub-supplierThe firm or organization, acceptable to the buyer, which supplies materials and/or services to the seller in conjunction with design or fabrication of the pressure vessel.3.1.14 vanadium-modified Cr-Mo steels 21/4Cr-1Mo-1/4V, 3Cr-1Mo-1/4V-Ti-B, and 3Cr-1Mo-1/4V-Cb-Ca steels, with no vanadium additions.3.2 AcronymsFor the purpose of this practice, the following acronyms apply:CMTR certified material test reportDHT dehydrogenation heat treatment4API TECHNICAL REPORT 934-BFN
