H2S腐蚀标准

Copyrig Provide No repr Standard Test Method Laboratory Testing of Metals for Resistance to Sulfide Stress Cracking and Stress Corrosion Cracking in H2S Environments This NACE International standard 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, whether he or she has adopted the standard or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not in conformance with this standard. Nothing contained in this NACE International standard 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 by Letters Patent, or as indemnifying or protecting anyone against liability for infringement of Letters Patent. This standard represents minimum requirements and should in no way be interpreted as a restriction on the use of better procedures or materials. Neither is this standard intended to apply in all cases relating to the subject. Unpredictable circumstances may negate the usefulness of this standard in specific instances. NACE International assumes no responsibility for the interpretation or use of this standard by other parties and accepts responsibility for only those official NACE International interpretations issued by NACE International in accordance with its governing procedures and policies which preclude the issuance of interpretations by individual volunteers. Users of this NACE International standard are responsible for reviewing appropriate health, safety, environmental, and regulatory documents and for determining their applicability in relation to this standard prior to its use. This NACE International standard may not necessarily address all potential health and safety problems or environmental hazards associated with the use of materials, equipment, and/or operations detailed or referred to within this standard. Users of this NACE International standard 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 requirements prior to the use of this standard. CAUTIONARY NOTICE: NACE International standards are subject to periodic review, and may be revised or withdrawn at any time in accordance with NACE technical committee procedures. NACE International requires that action be taken to reaffirm, revise, or withdraw this standard no later than five years from the date of initial publication. The user is cautioned to obtain the latest edition. 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Revised 2005-12-03 Revised 1996 Revised 1990 Revised 1986 Approved in 1977 NACE International 1440 South Creek Dr. Houston, Texas 77084-4906 +1 281/228-6200 ISBN 1-57590-036-X © 2005, NACE International NACE Standard TM0177-2005 Item No. 21212 ht NACE International d by IHS under license with NACE Licensee=SBL Technology Corp/5957378001 Not for Resale, 06/14/2006 07:06:36 MDToduction or networking permitted without license from IHS --``,`,`,``,````,,,,,,,```,,,,,-`-`,,`,,`,`,,`--- Copyright N Provided b No reprodu TM0177-2005 NACE International i ________________________________________________________________________ Foreword This standard addresses the testing of metals for resistance to cracking failure under the combined action of tensile stress and corrosion in aqueous environments containing hydrogen sulfide (H2S). This phenomenon is generally termed sulfide stress cracking (SSC) when operating at room temperature and stress corrosion cracking (SCC) when operating at higher temperatures. In recognition of the variation with temperature and with different materials this phenomenon is herein called environmental cracking (EC). For the purposes of this standard, EC includes only SSC, SCC, and hydrogen stress cracking (HSC). The primary purpose of this standard is to facilitate conformity in testing so that data from different sources can be compared on a common basis. Consequently, this standard aids the evaluation and selection of all types of metals and alloys, regardless of their form or application, for service in H2S environments. This standard contains methods for testing metals using tensile, bent-beam, C-ring, and double-cantilever-beam (DCB) test specimens. Certain ASTM(1) standard test methods have been listed as references for supplementary tests, creating a comprehensive test method standard. In addition, the four-point bent-beam test method is also referenced as a supplementary test.1,2 This standard is intended for use by laboratory and materials personnel to facilitate conformity in testing. SSC of metals exposed to oilfield environments containing H2S was recognized as a materials failure problem by 1952. Laboratory data and field experience have demonstrated that even extremely low concentrations of H2S may be sufficient to lead to SSC failure of susceptible materials. In some cases H2S can act synergistically with chlorides to produce corrosion and cracking (SSC and other mode) failures. However, laboratory and operating experiences have also indicated to materials engineers the optimum selection and specification of materials having minimum susceptibility to SSC. This standard covers test methods for SSC (at room temperature) and SCC (at elevated temperature), but other failure modes (e.g., hydrogen blistering, hydrogen- induced cracking [HIC], chloride stress corrosion cracking [SCC], pitting corrosion, and mass-loss corrosion) must also be considered when selecting materials for use in sour (H2S-containing) environments. The need for better understanding of the variables involved in EC of metals in oilfield environments and better correlation of data has become apparent for several reasons. New design requirements by the oil and gas production industries call for higher-strength materials that, in general, are more susceptible to EC than lower-strength alloys. These design requirements have resulted in extensive development programs to obtain more resistant alloys and/or better heat treatments. At the same time, users in the petroleum refining and synthetic fuels industries are pushing present materials much closer to their mechanical limits. Room-temperature (SSC) failures in some alloys generally are believed to result from hydrogen embrittlement (HE). When hydrogen is cathodically evolved on the surface of a metal (as by corrosion or cathodic charging), the presence of H2S (and other compounds, such as those containing cyanides and arsenic) tends to cause hydrogen atoms to enter the metal rather than to form hydrogen molecules that cannot enter the metal. In the metal, hydrogen atoms diffuse to regions of high triaxial tensile stress or to some microstructural configurations where they become trapped and decrease the ductility of the metal. Although there are several kinds of cracking damage that can occur in metals, delayed brittle fracture of metals resulting from the combined action of corrosion in an aqueous sulfide environment and tensile stresses (failure may occur at stresses far below the yield stress) is the phenomenon known as SSC. In some cases, however, failure may be the result of localized anodic corrosion processes that may or may not involve hydrogen. In such instances failure is the result of anodic stress corrosion cracking (SCC). Such failures have historically been termed SSC even though their cause may not be hydrogen. _________________ (1) ASTM International (ASTM), 100 Barr Harbor Dr., West Conshohocken, PA 19428-2959. - - ` ` , ` , ` , ` ` , ` ` ` ` , , , , , , , ` ` ` , , , , , - ` - ` , , ` , , ` , ` , , ` - - - ACE International y IHS under license with NACE Licensee=SBL Technology Corp/5957378001 Not for Resale, 06/14/2006 07:06:36 MDTction or networking permitted without license from IHS 1. General......................................................................................................................... 1 2. EC Testing Variability ................................................................................................... 1 Copyright Provided b No reprod , , ` ` ` , , , , , - ii NACE International 3. Reagents ...................................................................................................................... 2 4. Test Specimens and Material Properties ..................................................................... 2 5. Test Vessels and Fixtures ............................................................................................ 3 6. Test Solutions............................................................................................................... 3 7. Testing at Elevated Temperature/Pressure ................................................................. 4 8. Method A—NACE Standard Tensile Test .................................................................... 7 9. Method B—NACE Standard Bent-Beam Test............................................................ 13 10. Method C—NACE Standard C-Ring Test .................................................................. 20 11. Method D—NACE Standard DCB Test ...................................................................... 26 References........................................................................................................................ 37 Appendix A—Safety Considerations in Handling H2S Toxicity ......................................... 37 Appendix B—Explanatory Notes on EC Test Method....................................................... 38 FIGURE 1:Schematic Arrangement of Test Equipment for Method A—NACE Standard Tensile Test................................................................................................................... 5 FIGURE 2: Schematic Arrangement of Test Equipment for Method B—NACE Standard Bent-Beam Test, Method C—NACE Standard C-Ring Test, and Method D—NACE Standard Double-Cantilever Beam Test ....................................................................... 6 - - ` ` , ` , ` , ` ` , ` ` ` ` , , , , , NA y uc TM0177-2005 This standard was originally published in 1977 by NACE International Task Group T-1F-9, a component of Unit Committee T-1F on Metallurgy of Oilfield Equipment. The standard was revised in 1986, 1990, and 1996 by Task Group T-1F-9. It was revised in 2005 by Task Group (TG) 085 on Sulfide Corrosion Cracking: Metallic Materials Testing Techniques. TG 085 is administered by Specific Technology Group (STG) 32 on Oil and Gas Production—Metallurgy and is sponsored by STG 62 on Corrosion Monitoring and Measurement—Science and Engineering Applications. The standard is issued by NACE under the auspices of STG 32. In NACE standards, the terms shall, must, should, and may are used in accordance with the definitions of these terms in the NACE Publications Style Manual, 4th ed., Paragraph 7.4.1.9. Shall and must are used to state mandatory requirements. The term should is used to state something considered good and is recommended but is not mandatory. The term may is used to state something considered optional. ________________________________________________________________________ NACE International Standard Test Method Laboratory Testing of Metals for Resistance to Sulfide Stress Cracking and Stress Corrosion Cracking in H2S Environments Contents ` - ` , , ` , , ` , ` , , ` - - - CE International IHS under license with NACE Licensee=SBL Technology Corp/5957378001 Not for Resale, 06/14/2006 07:06:36 MDTtion or networking permitted without license from IHS Copyright NA Provided by No reproduc - - ` ` , ` , ` , ` ` , ` ` ` ` , , , , , , , ` ` ` , , , , , - ` - ` , , ` , , ` , ` , , ` - - - TM0177-2005 NACE International iii FIGURE 3: Tensile Test Specimens................................................................................... 8 FIGURE 4: Constant-Load (Dead-Weight) Device ........................................................... 10 FIGURE 5: Sustained-Load Devices ................................................................................ 11 FIGURE 6: Applied Stress vs. Log (Time-to-Failure)........................................................ 16 FIGURE 7: Dimensional Drawing of the Standard Bent-Beam Test Specimen ............... 17 FIGURE 8: Typical Stressing Fixture for Bent-Beam Test Specimen .............................. 18 FIGURE 9: Dimensional Drawing of the C-Ring Test Specimen...................................... 24 FIGURE 10: DCB Specimen............................................................................................. 30 Table 1—NACE Uniform Material Testing Report Form (Part 1): Testing in Accordance with NACE Standard TM0177 Method A—NACE Standard Tensile Test................... 14 Table 1—NACE Uniform Material Testing Report Form (Part 2): Testing in Accordance with NACE Standard TM0177 Method A—NACE Standard Tensile Test................... 15 Table 2—NACE Uniform Material Testing Report Form (Part 1): Testing in Accordance with NACE Standard TM0177 Method B—NACE Standard Bent-Beam Test ............ 22 Table 2—NACE Uniform Material Testing Report Form (Part 2): Testing in Accordance with NACE Standard TM0177 Method B—NACE Standard Bent-Beam Test ............ 23 Table 3—NACE Uniform Material Testing Report Form (Part 1): Testing in Accordance with NACE Standard TM0177 Method C—NACE Standard C-Ring Test ................... 27 Table 3—NACE Uniform Material Testing Report Form (Part 2): Testing in Accordance with NACE Standard TM0177 Method C—NACE Standard C-RingTest .................... 28 Table 4—Arm Displacements for API and Other Grade Oilfield Tubular Steels............... 31 Table 5—Suggested Arm Displacements for Selected Alloys and Strength Levels ......... 32 Table 6—NACE Uniform Material Testing Report Form (Part 1): Testing in Accordance with NACE Standard TM0177 Method D—NACE Standard DCB Test....................... 35 Table 6—NACE Uniform Material Testing Report Form (Part 2): Testing in Accordance with NACE Standard TM0177 Method D—NACE Standard DCB Test....................... 36 ________________________________________________________________________ CE International IHS under license with NACE Licensee=SBL Technology Corp/5957378001 Not for Resale, 06/14/2006 07:06:36 MDTtion or networking permitted without license from IHS 1.1 This standard covers the testing of metals subjected to of test specimen. General guidelines to help to determine the aptness of each test method are given at the beginning 1.3.1 For testing at ambient conditions, the test Method B The statistically based critical stress factor (Sc) _ e ___________________________ Copyrigh Provided No repro NACE International 1 (2) American Petroleum Institute (API), 1220 L St. NW, Washington, DC 20005. (3) International Organization for Standardization (ISO), 1 rue de Varembé, Case postale 56, CH-1211 Geneva 20, Switzerland. of each test method description (Sections 8 through 11). Reporting of the test results is also discussed. 1.3 Metals can be tested for resistance to EC at temperatures and pressures that are either ambient (atmospheric) or elevated. ____________________________________ Section 2: EC T 2.1 Interpretation of stress corrosion test results is a difficult task. The test methods contained in this standard are severe, with accelerated tests making the evaluation of the data extremely difficult. In testing the reproducibility of the test methods among different laboratories, several undesirable side effects (frequent with many accelerated tests) that must be noted include: 2.1.1 The test environment may cause failure by HIC and hydrogen blistering. This is especially true for lower-strength steels not usually subject to SSC. HIC may be detected by visual and metallographic observations. Blistering is normally visible on the test specimen surface. (For further information regarding this phenomenon, see NACE Standard TM0284.5) t NACE International by IHS under license with NACE L Nduction or networking permitted without license from IHS --``,`,`,``,````,,,,,,,```,,,,,-`-`,,`,,` for a 50% probability of failure in 720 hours. Method C The highest no-failure stress in 720 hours. Method D The average KISSC (threshold stress intensity factor for SSC) for valid tests of replicate test specimens. 1.5 Safety Precautions: H2S is an extremely toxic gas that must be handled with care. (See Appendix A.) ___________________________________ sting Variability 2.1.2 The test environment may corrode some alloys that normally do not corrode in actual field service and thereby induce EC failures in alloys that ordinarily do not fail by EC. This problem is especially acute with the martensitic and precipitation-hardened stainless steels. 2.2 Furthermore, other aspects to be considered in the selection of test method(s) include: 2.2.1 Material anisotropy affecting mechanical properties and EC susceptibility can be an important parameter. The fracture path in the test specimen should match what is anticipated in the actual component. Sections 1 through 7 of this standard give general comments that apply to all four test methods. Sections 8 through 11 indicate the test method to follow for each type informational purposes. This rating may be based on: Method A The highest no-failure stress in 720 hours. tensile stresses for resistance to cracking failure in low-pH aqueous environments containing H2S. Carbon and low- alloy steels are commonly tested for EC resistance at room temperature where SSC susceptibility is typically high. For other types of alloys the correlation of EC susceptibility with temperature is more complicated. 1.2 This standard describes the reagents, test specimens, and equipment to use, discusses base material and test specimen properties, and specifies the test procedures to follow. This standard describes four test methods: Method A—Standard Tensile Test Method B—Standard Bent-Beam Test Method C—Standard C-Ring Test Method D—Standard Double-Cantilever-Beam (DCB) Test ice ot ,`, procedures can be summarized as follows: Stressed test specimens are immersed in acidified aqueous environments containing H2S. Applied loads at convenient increments can be used to obtain EC data. 1.3.2 For testing at temperatures higher than 27°C (80°F), at either atmospher ic or elevated pressure, Section 7 describes an alternative test technique. All methods (A, B, C, and D) are adaptable to this technique. 1.4 This standard may be used for release or acceptance testing to ensure that the product meets a certain minimum level of EC resistance as prescribed in API(2) Specification 5CT,3 ISO(3) 11960,4 or as prescribed by the user or purchaser. This standard may also provide a quantitative measure of the product’s EC resistance for research or TM0177-2005 ________________________________________________________________________ Section 1: General nsee=