NACE 8X294-2013 Review of Published Literature on Wet H2S Cracking of Steels Through 1989 (Item No 24185).pdf

1、Item No. 24185 NACE International Publication 8X294 (2013 Edition) This Technical Committee Report has been prepared by NACE International Specific Technology Group (STG) 34,* “Review of Published Literature on Wet H2S Cracking of Steels Through 1989.” Review of Published Literature on Wet H2S Crack

2、ing of Steels Through 1989 December 2013, NACE International This NACE International (NACE) technical committee report represents a consensus of those individual members who have reviewed this document, its scope, and provisions. Its acceptance does not in any respect preclude anyone from manufactur

3、ing, marketing, purchasing, or using products, processes, or procedures not included in this report. Nothing contained in this NACE report is to be construed as granting any right, by implication or otherwise, to manufacture, sell, or use in connection with any method, apparatus, or product covered

4、by letters patent, or as indemnifying or protecting anyone against liability for infringement of letters patent. This report should in no way be interpreted as a restriction on the use of better procedures or materials not discussed herein. Neither is this report intended to apply in all cases relat

5、ing to the subject. Unpredictable circumstances may negate the usefulness of this report in specific instances. NACE assumes no responsibility for the interpretation or use of this report by other parties. Users of this NACE report are responsible for reviewing appropriate health, safety, environmen

6、tal, and regulatory documents and for determining their applicability in relation to this report prior to its use. This NACE report may not necessarily address all potential health and safety problems or environmental hazards associated with the use of materials, equipment, and/or operations detaile

7、d or referred to within this report. Users of this NACE report are also responsible for establishing appropriate health, safety, and environmental protection practices, in consultation with appropriate regulatory authorities if necessary, to achieve compliance with any existing applicable regulatory

8、 requirements prior to the use of this report. CAUTIONARY NOTICE: The user is cautioned to obtain the latest edition of this report. NACE reports are subject to periodic review, and may be revised or withdrawn at any time without prior notice. NACE reports are automatically withdrawn if more than 10

9、 years old. Purchasers of NACE reports may receive current information on all NACE International publications by contacting the NACE FirstService Department, 1440 South Creek Drive, Houston, Texas 77084-4906 (telephone +1 281-228-6200). Foreword This NACE technical committee report summarizes result

10、s of laboratory tests and investigations of field and plant experience presented in various sources of the published literature pertaining to the cracking of steels in wet hydrogen sulfide (H2S) service. Particular attention was devoted to the environmental, fabrication, and metallurgical parameters

11、 that play predominant roles in the cracking process. This technical committee report is an interpretational review of the literature. A bibliography is attached at the end of each section, and a reference list is also included at the end of the report, to assist readers who wish to seek further inf

12、ormation. A table cross-referencing AISI,(1)ASTM,(2)and UNS(3)designations for materials in this report is given in Appendix A. A review of this published literature appears to indicate that steels in refinery service have the potential to be subjected to conditions of hydrogen charging. These condi

13、tions result from the presence of H2S and possibly cyanide species in combination * John Wodarcyk, Phillips 66, Houston, TX (1)American Iron and Steel Institute (AISI), 1140 Connecticut Avenue, Suite 705, Washington, DC 20036. (2)ASTM International (ASTM), 100 Barr Harbor Drive, West Conshohocken, P

14、A 19428-2959. (3)Unified Numbering System for Metals and Alloys (UNS). UNS numbers are listed in Metals (2) Sulfide Stress Cracking; (3) Wet H2S Cracking: Refinery Experience; (4) Hydrogen-Induced Cracking: Pipeline Experience; (5) Inhibitors; and (6) Role of H2S in SCC in Amine Solutions. This NACE

15、 technical committee report was originally prepared in 1994 by Work Group T-8-16b and Task Group T-8-16 on Cracking in Wet H2S Environments. It was reaffirmed in 2003 and 2013 by Specific Technology Group (STG) 34 on Petroleum Refining and Gas Processing. This technical committee report is published

16、 under the auspices of STG 34. NACE technical committee reports are intended to convey technical information or state-of-the-art knowledge regarding corrosion. In many cases, they discuss specific applications of corrosion mitigation technology, whether considered successful or not. Statements used

17、to convey this information are factual and are provided to the reader as input and guidance for consideration when applying this technology in the future. However, these statements are not intended to be recommendations for general application of this technology, and must not be construed as such. T

18、erms and Mechanisms Hydrogen Blistering: The formation of subsurface planar cavities, called hydrogen blisters, in a metal resulting from excessive internal hydrogen pressure. Growth of near-surface blisters in low-strength metals usually results in surface bulges. As in sulfide stress cracking (SSC

19、), hydrogen blistering in steel involves the absorption and diffusion of atomic hydrogen produced on the metal surface by the sulfide corrosion process. The development of hydrogen blisters in steels is caused by the accumulation of hydrogen that recombines to form molecular hydrogen at internal sit

20、es in the metal. Typical sites for the formation of hydrogen blisters are large nonmetallic inclusions, laminations, or other discontinuities in the steel. This differs from the voids, blisters, and cracking associated with high-temperature hydrogen attack. Hydrogen-Induced Cracking (HIC): Stepwise

21、internal cracks that connect adjacent hydrogen blisters on different planes in the metal, or to the metal surface (also known as stepwise cracking). In steels, the development of internal cracks (sometimes referred to as blister cracks) tends to link with other cracks because of internal pressure re

22、sulting from the accumulation of hydrogen. The link-up of these cracks on different planes in steels is often referred to as “stepwise cracking” to characterize the nature of the crack appearance. HIC is commonly found in steels with (a) high impurity levels that have a high density of large planar

23、inclusions and/or (b) regions of anomalous microstructure produced by segregation of impurity and alloying elements in the steel. No externally applied stress is needed for the formation of HIC. Stress Corrosion Cracking (SCC): Cracking of a material produced by the combined action of corrosion and

24、sustained tensile stress (residual or applied). In alkaline environments, SCC in carbon steels sometimes occurs at moderately elevated temperatures because of the presence of various species in the environment such as carbonates, caustics, and amines. In some cases, the presence of cyanide and sulfi

25、de species increases the severity of cracking. The cracking is branched and intergranular in nature and typically occurs in non-stress-relieved steels. This form of cracking has often been referred to as carbonate cracking when associated with alkaline sour waters containing carbon dioxide (CO2), an

26、d as amine cracking when associated with alkanolamine treating solutions. Stress-Oriented Hydrogen-Induced Cracking (SOHIC): Arrays of cracks in steels, aligned nearly perpendicular to the applied stress, that are formed by the link-up of small HIC cracks in the steel. Tensile stress (residual and/o

27、r applied) produces SOHIC. SOHIC is commonly observed in the base metal adjacent to the heat-affected zone (HAZ) of a weld and is oriented in the through-NACE International 3 thickness direction. SOHIC is also produced in susceptible steels at other high stress points such as from the tip of mechani

28、cal cracks and defects and from the interaction between HIC on different planes in the steel. Sulfide Stress Cracking (SSC): Cracking of a material under the combined action of tensile stress and corrosion in the presence of water and hydrogen sulfide (a form of hydrogen stress cracking). SSC is a f

29、orm of hydrogen stress cracking involving atomic hydrogen that is produced by the sulfide corrosion process on the metal surface. The atomic hydrogen potentially diffuses into the metal and produces embrittlement. SSC usually occurs more readily in high-strength steels or in hard weld zones of steel

30、s. Section 1: Hydrogen Permeation in Steel 1.1 Summary 1.1.1 Overview of Hydrogen Permeation: Hydrogen-permeation measurements have been employed extensively in the laboratory to characterize the aggressiveness of diverse environments, to evaluate the effectiveness and appropriate concentrations of

31、inhibitors in reducing corrosion and hydrogen absorption, and to evaluate the ability of steels to resist initiation and propagation of hydrogen damage. A significant amount of hydrogen-permeation monitoring of linepipes containing wet sour gas has been undertaken using a variety of devices. Only li

32、mited monitoring of pressure vessels (refineries and heavy water plants) has been reported. Hydrogen-permeation monitoring activities are only applicable to those “wet H2S” cracking mechanisms in which absorbed hydrogen atoms play a role, e.g., hydrogen blistering, HIC, SOHIC, and SSC. 1.1.2 Materia

33、ls Grades and Product Forms: The bulk of the reported hydrogen-permeation work has been performed on API(4)linepipe steels, grades X42 through X75, and on ASTM A 3331grades 1 and 6 seamless pipe. Work on Japanese (ISIJ),(5)Canadian (CSA),(6)and German (DIN)(7)grades of linepipe steels has also been

34、reported. These linepipes have been fabricated in a variety of ways and include seamless, electric-resistance welded, and submerged-arc welded types. Additional work on high-purity iron, UNS G10100 (AISI 1010), a variety of mild steels, UNS G41300 (AISI 4130), UNS G43400 (AISI 4340), and high-streng

35、th low-alloy (HSLA) steels has been reported. Work has been performed on the following ASTM steels: UNS K02700 (A516)2grade 70 and UNS K02400 (A537)3class 1 pressure vessel plates, UNS K01803 (A633)4grade C structural steel, and UNS K12042 (A508)5class 3 and UNS K03011 (A350)6grade LF2 forgings. Tes

36、ting of 2.25 Cr-1 Mo steel plate has also been reported. The steels have been produced by both conventional and more modern techniques such as vacuum degassing, electroslag remelting, calcium treating, and continuous casting. Hydrogen-permeation measurements have been made on steels that have underg

37、one additional refinement, microalloying, and/or special processing procedures. In particular, the effects on hydrogen permeation of lowering carbon, manganese, phosphorus, and sulfur levels and of microalloying have been investigated. 1.1.3 Environments: Electrochemical cathodic charging environmen

38、ts have been used extensively in the development of hydrogen-permeation monitoring devices and in the characterization of steels, e.g., to determine threshold concentrations for initiation of hydrogen damage. A large number of sour environments have been employed in the laboratory, including H2S in

39、pure water, NACE Standard TM0177,7NACE Standard TM0284,8ASTM D11419solutions with varying amounts of acetic acid, NaCl, and sodium acetate. Corrosion inhibitors and other chemicals (e.g., glycol, cyanide, polysulfide) have been added to these environments in some studies. Initial pH values have rang

40、ed from 2.6 to 8.8. Most work has been performed in these environments in equilibrium with 0.1 MPa (1 atm) H2S. CO2and H2S mixtures have been used in some experiments. Test temperatures have ranged from 10 to 60 C (14 to 140 F) with the majority of tests performed at 25 C (77 F). Some full-scale tes

41、ts have been performed at elevated pressures (to 19 MPa 2,700 psi). A variety of field environments have been monitored. 1.1.4 Types of Hydrogen-Permeation Monitoring Instruments: Devices based on electrochemical principles have been used for the majority of laboratory and field hydrogen-permeation

42、monitoring studies. Limited laboratory and field data have been developed using hydrogen pressure build-up and vacuum devices. (4)American Petroleum Institute (API), 1220 L St. NW, Washington, DC 20005. (5)Iron and Steel Institute of Japan (ISIJ), Keidranren Kaikan, Third Floor, 1-9-4 Otemachi, Chiy

43、oda-ku, Tokyo, 100-0004, Japan. (6)CSA International (CSA), 178 Rexdale Blvd., Etobicoke, Ontario, M9W 1R3 Canada. (7)Deutches Institut fur Normung (DIN), Burggrafenstrasse 6, D-10787 Berlin, Germany. NACE International 4 1.2 Overview Discussion 1.2.1 Important Trends in the Data 1.2.1.1 Equipment a

44、nd Techniques for Laboratory Measurements: The majority of laboratory work involving hydrogen-permeation measurements has been performed using electrochemical techniques. The theory behind these techniques and descriptions of the apparatus used have been given particular attention in the literature.

45、 A potentiostat, reference electrode, and alkaline solution have often been employed to apply a fixed potential to the monitored steel surface. Emergent hydrogen atoms were oxidized and detected by current flow in the cell. Concentrations of diffusing hydrogen were then calculated through applicatio

46、n of electrochemical and diffusion theory. Greater sensitivity and more quantitative results were claimed to be benefits of plating palladium or nickel onto the monitored surface. Sealed-cell devices have become more common for hydrogen-permeation studies. These devices often have solid electrolytes

47、 or liquid electrolytes. Claimed advantages include increased life and wider temperature range of operation. Some sealed-cell devices have sacrificial steel membranes that are exposed to the environment of interest, and others have thin palladium foils that are attached with wax to the steel surface

48、 to be monitored. A high-temperature device has also been described. Pressure build-up devices have been used in some laboratory studies. Permeating hydrogen has been detected through pressure monitoring or by a technique involving displacement of glycerine or mercury from a measuring cylinder. Vacu

49、um devices have also been employed in laboratory studies. Permeating hydrogen was detected with an ion pump or a mass spectrometer. 1.2.1.2 Equipment and Techniques for Field and Plant Measurements: The types of hydrogen-permeation monitoring devices used in the field until the mid-1980s have been reviewed. Most work using these devices has been performed in the field in connection with refineries. Monitoring of plants producing heavy water by the Geib-Spevack process has occurred. Devices that have been used to monitor permeating hydrogen from vessels in wet, sour environments incl