1、 Test Method Evaluation of Pipeline and Pressure Vessel Steels for Resistance to Hydrogen-Induced Cracking 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 a
2、nyone, 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 ot
3、herwise, 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 r
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7、afety 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,
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9、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 and subsequently from the date of each reaffirmation or revision. The user is cau
10、tioned to obtain the latest edition. Purchasers of NACE International standards may receive current information on all standards and other NACE International publications by contacting the NACE International FirstService Department, 15835 Park Ten Place, Houston, Texas 77084-5145 (telephone +1 281-2
11、28-6200). Approval 2016-3-22 Revised 2011-10-28 Revised 2003-01-17 Revised 1996-Mar-30 Reaffirmed 1987-Mar Approved 1984-Feb ISBN: 1-57590-163-3 NACE International 15835 Park Ten Place Houston, TX 77084-5145 +1 281-228-6200 2016 NACE InternationalNACE TM0284-2016 Item No. 21215 TM0284-2016 NACE Inte
12、rnational i _ Foreword Absorption of hydrogen generated by corrosion of steel in a wet hydrogen sulfide (H2S) environment can have several effects that depend on the properties of the steel, manufacturing or forming processes, the characteristics of the environment, and other variables. One adverse
13、effect observed in pipeline and pressure vessel steels is the development of cracks along the rolling direction of the steel. Cracks on one plane tend to link up with the cracks on adjacent planes to form steps across the thickness. The cracks can reduce the effective wall thickness until the pipeli
14、ne or pressure vessel becomes overstressed and ruptures. Cracking is sometimes accompanied by surface blistering. Several service failures attributed to such cracking have been reported.1,2 The terms stepwise cracking (SWC), hydrogen pressure cracking, blister cracking, and hydrogen-induced stepwise
15、 cracking have been used in the past to describe cracking of this type in pipeline and pressure vessel steels, but are now considered obsolete. The term hydrogen-induced cracking (HIC) has been widely used for describing cracking of this type, and has been adopted by NACE International. Therefore, i
16、t is used throughout this standard test method. HIC is related to hydrogen blistering, which has been recognized since the 1940s as a problem in pressure vessels handling sour products.3 It was not until much later, however, that HIC gained wide recognition as a potential problem in pipelines. As a
17、result of pipeline failures experienced by two companies in the early 1970s, several companies began investigating the cracking and publishing results of tests on various steels. Many investigators found, however, that they could not reproduce published test results. It was eventually determined tha
18、t lack of reproducibility resulted largely from differences in test procedures. Consequently, NACE Unit Committee T-1F, “Metallurgy of Oilfield Equipment,” established Task Group (TG) T-1F-20, “Stepwise Cracking of Pipeline Steels,” to study the problem and prepare a standard test method. This stand
19、ard was originally prepared in 1984 to provide a standard set of test conditions for consistent evaluation of steel pipes and for comparison of test results from different laboratories. Subsequently, the concern for HIC damage turned to steel plates used for pressure vessels. Requirements for testin
20、g steel plates for resistance to HIC were included in this standard in 1996. More recently, concern for HIC damage in steel fittings and flanges used in pipelines and pressure vessels led to their inclusion in the 2011 revision of this standard. Therefore, the scope of this standard now includes the
21、 testing of steels furnished in the form of pipes, plates, fittings, and flanges for use in fabricating pipelines and pressure vessels. In the 2016 revision of this standard, Fitness-For-Purpose testing in an alternative test solution, to be used with gas containing mixtures of H2S and CO2, was incl
22、uded to assess HIC damage under mildly sour test conditions with reduced partial pressure of H2S in a range of pH values. Test conditions are not designed to simulate any particular pipeline or process operation, even though in Fitness-for-Purpose tests, partial pressures of H2S and pH values approp
23、riate to the intended application must be selected. The test is intended to evaluate resistance to HIC only, and not to other adverse effects of sour environments such as sulfide stress cracking (SSC), pitting, or mass loss from corrosion. This test may be used for many purposes, and the application
24、s of the results are beyond the scope of this standard. Those who use the test should be aware that in some cases, test results can be influenced by variations in properties among different locations in a single length of pipe or individual plate, fitting, or flange, as well as by variations within
25、a heat of steel. When the test is used as a basis for purchasing, the number and location of test specimens must be carefully considered.4 This standard is intended for end users, manufacturers, fabricators, and testing laboratories. This standard was originally prepared by TG T-1F-20 in 1984. It wa
26、s revised in 1996 by TG T-1F-20, and in 2003, 2011, and 2016 by TG 082, “Stepwise Cracking of Pipeline Steels,” which is administered by Specific Technology Group (STG) 32, “Oil and Gas Production Metallurgy” and sponsored by STG 34, “Petroleum Refining and Gas Processing,” and STG 62, “Corrosion Mo
27、nitoring and MeasurementScience and Engineering Applications.” It 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. The terms shall and must are u
28、sed to state a requirement, and are considered mandatory. The term should is used to state something good and is recommended, but is not considered mandatory. The term may is used to state something considered optional. TM0284-2016 ii NACE International _ NACE International Test Method Evaluation of
29、 Pipeline and Pressure Vessel Steels for Resistance to Hydrogen-Induced Cracking Contents 1. General 1 2. Reagents . 1 3. Testing Apparatus 2 4. Test Specimens- Pipes 2 5. Test Specimens-Plates 6 6. Test Specimens-Fittings 8 7. Test Specimens- Flanges . 11 8. Test Procedures . 12 9. Evaluations of T
30、est Specimens . 15 10. Reporting Test Results 16 References 17 Appendix A: Evaluation of Hydrogen Induced Cracking by Ultrasonic Testing (Nonmandatory) 19 Appendix B: Safety Considerations in Handling H2S Toxicity (Nonmandatory) 24 Appendix C: Explanatory Notes on Test Method (Nonmandatory) 25 Appen
31、dix D: Determination of H2S Concentration in Test Solution by Iodometric Titration (Nonmandatory) 26 Figure Figure 1: Schematic Diagram of Typical Test Assembly2 Figure 2: Seamless Pipe and Parent Metal of Longitudinally Welded Pipe (All Dimensions in mm 1 in = 25.4 mm) 3 Figure 3: Weld Area of Long
32、itudinally Welded Pipe or Welded Fittings (All Dimensions in mm 1 in = 25.4 mm) 3 Figure 4: Weld Area of ERW Pipe (All Dimensions in mm 1 in = 25.4 mm) .4 Figure 5 (a): Parent Metal of Spiral-Welded Pipe (All Dimensions in mm 1 in = 25.4 mm)5 Figure 5 (b): Location and Orientation of Test Specimens
33、to Be Taken from Spiral-Welded .5 Figure 6: Weld Area of Spiral-Welded Pipe (All Dimensions in mm 1 in = 25.4 mm) Pipe).6 Figure 7: Test Specimen Location for Plates up to 30 mm (1.2 in) Thick, Inclusive (All Dimensions in mm 1 in = 25.4 mm) .7 Figure 8: Test Specimen Location for Plates 30 mm (1.2
34、in) to 88 mm (3.5 in) Thick, Inclusive (All Dimensions in mm 1 in = 25.4 mm) .7 Figure 9: Test Specimen Location for Plates over 88 mm (3.5 in) Thick (All Dimensions in mm 1 in = 25.4 mm) . 8 Figure 10: Orientation of Test Specimens in the Test Vessel.12 Figure 11: Test Specimen and Crack Dimensions
35、 to Be Used in Calculating CSR, CLR, and CTR. 16 _ TM0284-2016 NACE International 1 _ Section 1: General 1.1 This standard establishes a test method for evaluating the resistance of pipeline and pressure vessel steels to HIC caused by hydrogen absorption from aqueous sulfide corrosion. 1.1.1 Details
36、 are provided on the size, number, location, and orientation of test specimens to be taken from each steel product formpipes, plates, fittings, and flanges. 1.1.2 Special procedures or requirements for testing small-diameter (nominal diameter DN 50 through 150, nominal pipe size NPS 2 through 6), th
37、in-wall (up to 6 mm 0.2 in wall thickness), electric-resistance welded (ERW) and seamless pipes are included. The test specimens taken from small-diameter, thin-wall pipes shall be tested in the same manner as the test specimens taken from other pipes except as otherwise stated in this standard. 1.2
38、 The test method consists of exposing unstressed test specimens to one of the three standard test solutionsTest Solution A, an acidified brine solution consisting of sodium chloride (NaCl) and acetic acid (CH3COOH) dissolved in distilled or deionized water saturated with H2S at ambient temperature a
39、nd pressure; or Test Solution B, a synthetic seawater solution saturated with H2S at ambient temperature and pressure; or Test Solution C, a buffered solution consisting of sodium chloride (NaCl) and sodium acetate (CH3COONa) dissolved in distilled or deionized water saturated with gas containing mi
40、xtures of H2S and CO2 at ambient temperature and pressure enabling testing to be conducted at different H2S partial pressures in the range 0.001 to 1 bar. After a specified time, the test specimens are removed and evaluated. NOTE: The length of the test may not be sufficient to develop maximum crack
41、ing in any given steel, but has been found to be adequate for the purpose of this test. 1.3 In Fitness-for-Purpose testing, the test environment and partial pressures of gases appropriate to the intended application are selected. NOTE: The test conditions do not duplicate all aspects of service cond
42、itions, for example temperature, but will allow sufficient discrimination of the applicability of candidate steels. See Paragraph 8.1.5 and associated notes. 1.4 This standard does not include acceptance or rejection criteria; however, guidance is provided in NACE MR0175/ISO(1) 15156,5 Part 2, Secti
43、on 8 and Annex B of EFC(2) 16.6 1.5 For additional information, the presence or absence of HIC in the exposed specimens may be evaluated by automated ultrasonic testing prior to metallographic sectioning and examination. A procedure is provided in Appendix A (nonmandatory). _ Section 2: Reagents 2.1
44、 The reagents for Test Solution A shall be an inert gas (nitrogen, argon, or other suitable non-reactive gas) for purging, H2S gas, NaCl, CH3COOH, and distilled or deionized water. The reagents for Test Solution B shall be an inert gas for purging, H2S gas, and synthetic seawater. The reagents for T
45、est Solution C shall be an inert gas for purging, a mixture of H2S and carbon dioxide (CO2), with H2S content sufficient to produce the specified H2S partial pressure, NaCl, CH3COONa, hydrochloric acid (HCl) or sodium hydroxide (NaOH) added to achieve the specified pH and distilled or deionized wate
46、r. NOTE: H2S is highly toxic and must be handled with caution. See Appendix B (nonmandatory). 2.2 The NaCl, CH3COOH, CH3COONa, HCl and NaOH shall be reagent grade chemicals. (1) International Organization for Standardization (ISO), Chemin de Blandonnet 8. Case Postale 401, 1214 Vermier, Geneva, Swit
47、zerland. (2) European Federation of Corrosion (EFC), 1 Carlton House Terrace, London, SW1Y 5DB, U.K. TM0284-2016 2 NACE International 2.3 The inert gas purity shall be 99.998% or greater. The H2S gas shall be chemically pure (CP grade) 99.5% minimum purity. Test gas mixtures consisting of H2S and CO2 should be contained in a standard gas cylinder equipped with a suitable pressure regulator (usually stainless steel) capable of gas delivery to the total test pressure required. A commercially supplied gas mixture with composition determined by
