1、Steels for Hydrogen Service at Elevated Temperatures and Pressures in Petroleum Refineries and Petrochemical PlantsAPI RECOMMENDED PRACTICE 941 EIGHTH EDITION, FEBRUARY 2016Special NotesAPI publications necessarily address problems of a general nature. With respect to particular circumstances, local
2、, state, and federal laws and regulations should be reviewed.Neither API nor any of APIs employees, subcontractors, consultants, committees, or other assignees make any warranty or representation, either express or implied, with respect to the accuracy, completeness, or usefulness of the information
3、 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 nor any of APIs employees, subcontractors, consultants, or other assignees represent that use of this publication would not i
4、nfringe 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 reliability of the data contained in them; however, the Institute makes no representation, warranty, or guarantee in connection with th
5、is 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 jurisdiction with which this publication may conflict.API publications are published to facilitate the broad availability of proven,
6、sound engineering and operating practices. These publications are not intended to obviate the need for applying sound engineering judgment regarding when and where these publications should be utilized. The formulation and publication of API publications is not intended in any way to inhibit anyone
7、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 complying with all the applicable requirements of that standard. API does not represent, warrant, or guarantee that such products d
8、o in fact conform to the applicable API standard.Classified areas may vary depending on the location, conditions, equipment, and substances involved in any given situation. Users of this Recommended Practice should consult with the appropriate authorities having jurisdiction.Users of this Recommende
9、d Practice should not rely exclusively on the information contained in this document. Sound business, scientific, engineering, and safety judgment should be used in employing the information contained herein.API is not undertaking to meet the duties of employers, manufacturers, or suppliers to warn
10、and properly train and equip their employees, and others exposed, concerning health and safety risks and precautions, nor undertaking their obligations to comply with authorities having jurisdiction.Information concerning safety and health risks and proper precautions with respect to particular mate
11、rials and conditions should be obtained from the employer, the manufacturer or supplier of that material, or the material safety data sheet.Where applicable, authorities having jurisdiction should be consulted.Work sites and equipment operations may differ. Users are solely responsible for assessing
12、 their specific equipment and premises in determining the appropriateness of applying the Recommended Practice. At all times users should employ sound business, scientific, engineering, and judgment safety when using this Recommended Practice.All rights reserved. No part of this work may be reproduc
13、ed, translated, stored in a retrieval system, or transmitted by any means, 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 2016 Americ
14、an Petroleum InstituteForewordNothing contained in any 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 product covered by letters patent. Neither should anything contained in the publication be cons
15、trued as insuring anyone against liability for infringement of letters patent.Shall: As used in a standard, “shall” denotes a minimum requirement in order to conform to the specification.Should: As used in a standard, “should” denotes a recommendation or that which is advised but not required in ord
16、er to conform to the specification.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 c
17、omments and questions concerning 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 mater
18、ial published herein should also be addressed 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 St
19、andards 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 submitted to the Standards Department, API, 1220 L Street, NW, Washington, DC 20005, standards
20、api.org.iiiContentsPage1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Normative References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
21、 . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Operating Experience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23.1 Basis for Setting Integrity Operating Windows . . . . . . . . . . . . . . . .
22、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23.2 Selecting Materials for New Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23.3 High Temperature Hydrogen Attack (HTHA) in a Liquid Hydrocarbon Phase . . . . .
23、. . . . . . . . . . . . . . . . . . 43.4 Base Material for Refractory-lined Equipment or Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43.5 References and Comments for Figure 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
24、 . . . . . . . . . . . . 44 Forms of HTHA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74.2 Surface Decarburization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84.3 Internal Decarburization, Fissuring, and Cracking . . . . . . . . .
26、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 Factors Influencing Internal Decarburization, Fissuring, and Cracking Caused by HTHA . . . . . . . . . . . . 95.1 Incubation Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
27、. . . . . . . . . . . . . . . . . . . . . . . . . . . 95.2 Effect of Primary Stresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115.3 Effect of Secondary Stresses. . . . . . . . . . . . . . . . . . . . . . . . . .
28、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115.4 Effect of Heat Treatment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115.5 Effect of Stainless Steel Cladding or Weld Overlay . . . .
29、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 Inspection for HTHA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136.1 General . . . . . . . . . . . . . . . . . . . . . . .
30、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136.2 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14Annex A (info
31、rmative) HTHA of 0.5Mo Steels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15Annex B (informative) HTHA of 1.25 Cr-0.5Mo Steel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25Annex C (inf
32、ormative) HTHA of 2.25Cr-1Mo Steel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27Annex D (informative) Effective Pressures of Hydrogen in Steel Covered by Clad/Overlay . . . . . . . . . . . . . . . 29Annex E (informative) Summary of Inspection
33、Methods. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30Annex F (informative) HTHA of Non-PWHTd Carbon Steels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34Annex G (informative) Methodology for Calculating Hydrogen Part
34、ial Pressure in Liquid-filled Piping . . . . . 37Annex H (informative) Internal Company Data CollectionRequest for New Information. . . . . . . . . . . . . . . . . 41Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
35、 . . . . . . . . . . . . . . . . . . . 43Figures1 Operating Limits for Steels in Hydrogen Service to Avoid High Temperature Hydrogen Attack . . . . . . . 32 C-0.5Mo Steel (ASTM A204 Grade A) Showing Internal Decarburization and Fissuring in High Temperature Hydrogen Service . . . . . . . . . . . . .
36、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Incubation Time for High Temperature Hydrogen Attack Damage of Carbon Steel (Non-welded or Welded with Postweld Heat Treatment) in High Temperature Hydrogen Service. . . . . . . . . . . . . . . . . 10A.1 Experi
37、ence with C-0.5Mo and Mn-0.5Mo Steel in High Temperature Hydrogen Service . . . . . . . . . . . . . 16vContentsPageA.2 Steels in High Temperature Hydrogen Service Showing Effect of Molybdenum and Trace Alloying Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
38、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22A.3 Incubation Time for High Temperature Hydrogen Attack Damage of 0.5Mo Steels in High Temperature Hydrogen Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
39、 23B.1 Operating Conditions for 1.25Cr-0.5Mo Steels That Experienced High Temperature Hydrogen Attack Below the Figure 1 Curve. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26C.1 Operating Conditions of 2.25Cr-1Mo Steels That Exp
40、erienced High Temperature Hydrogen Attack Below the Figure 1 Curve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28F.1 Operating Conditions for Carbon Steel (Welded with No PWHT) That Experienced HTHA Below the 1977
41、Carbon Steel Figure 1 Curve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35TablesA.1 Operating Conditions for C-0.5Mo Steels That Experienced High Temperature Hydrogen Attack Below the 0.5Mo Steel Curve in Figure A.1 . . . . . . . . . .
42、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21A.2 References Along with Chromium, Molybdenum, Vanadium and Molybdenum Equivalent Values for Figure A.2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
43、. . . . . . . . . . . . 24B.1 Experience with HTHA of 1.25Cr-0.5Mo Steel at Operating Conditions Below the Figure 1 Curve. . . . . 25C.1 Experience with High Temperature Hydrogen Attack of 2.25Cr-1Mo Steel at Operating Conditions Below the Figure 1 Curve . . . . . . . . . . . . . . . . . . . . . . .
44、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27E.1 Summary of Ultrasonic Inspection Methods for High Temperature Hydrogen Attack . . . . . . . . . . . . . . . 31E.2 Summary of Non-ultrasonic Inspection Methods for High Temperature Hydrogen Attack . . . . . . . . . . . 33G.1 Effec
45、tive Hydrogen Partial Pressures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39G.2 Effective Hydrogen Partial Pressures with the Composition Variation + Compensation Method. . . . . . 40viIntroductionAt normal atmospheric temperatures,
46、gaseous molecular hydrogen does not readily permeate steel, even at high pressures. Carbon steel is the standard material for cylinders that are used to transport hydrogen at pressures of 2000 psi (14 MPa). Many postweld heat treated carbon steel pressure vessels have been used successfully in conti
47、nuous service at pressures up to 10,000 psi (69 MPa) and temperatures up to 430 F (221 C). However, under these same conditions, highly stressed carbon steels and hardened steels have cracked due to hydrogen embrittlement.The recommended maximum hydrogen partial pressure at atmospheric temperature f
48、or carbon steel fabricated in accordance with the ASME Boiler and Pressure Vessel Code is 13,000 psia (90 MPa). Below this pressure, carbon steel equipment has shown satisfactory performance. Above this pressure, very little operating and experimental data are available. If plants are to operate at
49、hydrogen partial pressures that exceed 13,000 psia (90 MPa), the use of an austenitic stainless steel liner with venting in the shell should be considered.At elevated temperatures, molecular hydrogen dissociates into the atomic form, which can readily enter and diffuse through the steel. Under these conditions, the diffusion of hydrogen in steel is more rapid. As discussed in Section 4, hydrogen reacts with the carbon in the steel to cause either surface decarburization or internal decarburization and fissuring, and eventual cracking. This form of hydrogen damage is called high temper
