1、 Standard Test Method Slow Strain Rate Test Method for Evaluation of Ethanol Stress Corrosion Cracking in Carbon Steels 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 respe
2、ct 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 impl
3、ication 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 inter
4、preted 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 in
5、terpretation 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. U
6、sers 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
7、 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 protecti
8、on 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 with
9、drawn 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. Purchasers of N
10、ACE International standards may receive current information on all standards and other NACE International publications by contacting the NACE International FirstService Department, 1440 South Creek Drive, Houston, Texas 77084-4906 (telephone +1 281-228-6200). NACE International 1440 South Creek Dr.
11、Houston, Texas 77084-4906 +1 281-228-6200 ISBN 1-57590-242-7 2011, NACE International NACE Standard TM0111-2011 Item No. 21255 TM0111-2011 NACE International i _ Foreword This standard establishes a slow strain rate (SSR) test method for evaluating susceptibility of carbon steels to ethanol stress c
12、orrosion cracking (SCC). It relates to the evaluation of SCC that may be observed in equipment involved in handling, storage, and transportation of ethanolic environments. This equipment primarily includes storage tanks and pipeline system components typically associated with the distribution of eth
13、anolic environments, which include fuel grade ethanol (FGE) and blends of FGE with hydrocarbon fuels (hereinafter referred to as FGE-fuel blends). This test method may also be used for research related to the effects of environmental or metallurgical variables on susceptibility to ethanol SCC. Field
14、 samples of FGE and FGE-fuel blends present under natural service conditions, as well as synthetic ethanolic solutions prepared in the laboratory, may be used with this test method. This standard does not address (a) all of the possible test methods that may be applied to evaluation of ethanol SCC,
15、(b) related issues of selection of materials, fabrication methods, and construction methods for equipment in ethanol service, or (c) fitness-for-service evaluation of equipment. Evaluations of ethanol SCC to date have been performed primarily on carbon steels with predominantly ferritic and pearliti
16、c microstructures that are commonly used in storage tanks and pipeline system components. The procedures cited in this test method are based on the techniques developed for the purpose of evaluating these carbon steel materials for ethanol SCC. This test method may serve as a basis for testing other
17、 types of steels and materials for susceptibility to SCC in ethanolic environments. This test method may also serve as a basis for testing various materials for SCC in other alcoholic environments (e.g., methanol, butanol). If this test method is used for testing materials other than carbon steels f
18、or ethanol SCC, or for testing various materials for SCC in other alcoholic environments, the procedures cited herein may need to be adapted or changed to be applicable. This standard is intended for use by researchers and engineers tasked with evaluation of SCC in ethanolic environments. For correc
19、t and accurate application, this standard should be used in its entirety. Using or citing only specific sections or paragraphs may lead to misapplication of the test method contained in this standard or misinterpretation of the test results obtained using this standard. TM0111-2011 ii NACE Internati
20、onal This standard was prepared by Task Group (TG) 387, Biofuels. TG 387 is administered by Specific Technology Group (STG) 35, Pipelines, Tanks, and Well Casings, and sponsored by STG 34, Petroleum Refining and Gas Processing; STG 36, Process IndustryMaterials Performance in Chemicals; STG 38, Proc
21、ess IndustryPulp, Paper, and Biomass Conversion; STG 43, Transportation, Land; STG 44, Marine CorrosionShips and Structures; STG 61, InhibitionCorrosion and Scaling; and STG 62, Corrosion Monitoring and MeasurementScience and Engineering Applications. This standard is issued by NACE International un
22、der the auspices of STG 35. 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 used to state a requirement, and are considered mandatory. The term should is used to s
23、tate something good and is recommended, but is not considered mandatory. The term may is used to state something considered optional. _ TM0111-2011 NACE International iii _ NACE International Standard Test Method Slow Strain Rate Test Method for Evaluation of Ethanol Stress Corrosion Cracking in Car
24、bon Steels Contents 1. General 1 2. Test Environments 2 3. Test Specimens . 3 4. Test Equipment . 7 5. Determination of Baseline Material Properties 7 6. Environment Test Condition 8 7. Mechanical Test Conditions 9 8. Test Procedure 9 9. Data Analysis and Reporting . 10 References 12 Appendix A: Met
25、hods for Analysis of Data from SSR Testing (Nonmandatory) . 13 FIGURES Figure 1: Standard SSR test specimen with optional notch (total length and threading/gripping details are not indicated). 5 _ TM0111-2011 NACE International 1 _ Section 1: General 1.1 This standard establishes a SSR test method f
26、or evaluating susceptibility of carbon steels to ethanol SCC. It relates to the evaluation of SCC that may be observed in equipment involved in handling, storage, and transportation of ethanolic environments. This equipment primarily includes storage tanks and pipeline system components typically as
27、sociated with the distribution of ethanolic environments, which includes FGE and FGE-fuel blends. This test method may also be used for research related to the effects of environmental or metallurgical variables on susceptibility to ethanol SCC. Field samples of FGE and FGE-fuel blends present under
28、 natural service conditions, as well as synthetic ethanolic solutions prepared in the laboratory, may be used with this test method. 1.2 This test method is an evaluation method for screening or ranking susceptibility of carbon steels to ethanol SCC or for determination of the propensity of ethanoli
29、c environments to produce ethanol SCC in carbon steels. Further research or field experience may be required before using the results in engineering decisions. 1.3 This standard addresses the test environments, test specimens, test equipment, determination of baseline material properties, environmen
30、t test conditions, mechanical test conditions, test procedure, data analysis and reporting of test results. 1.4 Two types of SSR test specimens are allowed in this standard: (a) a notched tensile test specimen, and (b) a nonnotched tensile test specimen. 1.5 The test procedure is summarized as follo
31、ws: A SSR test specimen is exposed to a continuously increasing uniaxial tensile stress imposed by a slow and constant extension rate in the presence of an ethanolic environment until fracture is observed. The environment test results include: (a) determination of the tensile strength, (b) determina
32、tion of the plastic elongation, and (c) assignment of the fracture classification based on examination of the fracture surface morphology. A similar SSR test specimen is pulled at the same extension rate in the presence of an inert environment (e.g., laboratory air) to determine the baseline values
33、of tensile strength and plastic elongation. The ratios of the tensile strength and plastic elongation values in the environment test to their respective average baseline values are determined. 1.6 The values of tensile strength and plastic elongation determined in the environment test, the ratios of
34、 tensile strength and plastic elongation in the environment test to their respective average baseline values, and the fracture classification based on the fracture surface morphology in the environment test serve as indicators of the SSR test specimen materials susceptibility to SCC in the ethanolic
35、 test environment. Ratio values that approach 1.0 indicate high resistance to SCC, whereas lower ratio values normally indicate some degree of susceptibility to SCC. 1.7 Acceptance criteria based on values of tensile strength and plastic elongation in the environment test, ratios of the tensile stre
36、ngth and plastic elongation values in the environment test to their respective average baseline values, and fracture classification based on the fracture surface morphology in the environment test are outside the scope of this standard. It shall be the responsibility of the user to define the limits
37、 of acceptable behavior for these SSR test results. 1.8 Procedures for SSR testing shall be consistent with those provided in ASTM(1) G129,1 unless specifically defined differently herein. 1.9 Other optional techniques may be used as required for particular applications of the data, but these are be
38、yond the scope of this standard. These techniques may involve: (a) fracture energy, (b) crack growth rate, and (c) in the case of a notched SSR test specimen, application of fracture mechanics. (1) ASTM International (ASTM), 100 Barr Harbor Dr., West Conshohocken, PA 19428-2959. TM0111-2011 2 NACE I
39、nternational _ Section 2: Test Environments 2.1 The test environments may be field samples of FGE or FGE-fuel blends, or synthetic ethanolic solutions prepared in the laboratory by mixing reagent grade ethanol with additions of other chemicals. Field samples of FGE may be obtained by sampling at any
40、 point between the FGE manufacturing site and the location at which it is blended with fuel. Field samples of FGE-fuel blends may be obtained by sampling at any point in the distribution system after the FGE is blended with fuel, either intentionally to produce a specific product or unintentionally
41、from transmixtures of fluids produced in pipelines or by other means whereby FGE is contacted by other hydrocarbon products. Field samples of FGE or FGE-fuel blends from different sources, or synthetic ethanolic solutions of different chemical composition, may produce varying SCC behavior. More info
42、rmation is available in published literature.26 2.2 If field samples of FGE or FGE-fuel blends are to be tested, the source and the manufacturing method of the FGE shall be recorded. Field samples of FGE or FGE-fuel blends shall be obtained in a dry, sealable container made of material inert to the
43、sample media and rinsed with ethanol prior to sampling. Sampling shall be performed while excluding ambient air and moisture using dry air to purge the sample container prior to and during transfer for aerated conditions or nitrogen for deaerated conditions. The sample container shall be filled to m
44、ore than 90% of its volume to minimize the vapor space in the container. After the sample has been obtained, the vapor space in the container shall be purged with dry air or nitrogen consistent with the purge gas used during sampling, and the container immediately sealed tightly. 2.3 To facilitate t
45、he comparison of data between laboratories, a standard synthetic ethanolic solution has been developed that, when aerated, has a high propensity to produce ethanol SCC in carbon steels. This standard synthetic ethanolic solution is based on a mixture of reagent grade ethanol with additions of water,
46、 methanol, acetic acid, and inorganic chloride. An addition of natural gasoline (i.e., without any fuel additives) as a denaturant is optional. 2.3.1 The composition of the standard synthetic ethanolic solution shall be as follows: 1 vol% distilled water 0.5 vol% methanol 56 mg/L acetic acid 32 mg/L
47、 inorganic chloride added as sodium chloride (NaCl) Optional: 3.75 vol% natural gasoline, without any fuel additives (as a denaturant) Balance: reagent grade ethanol 2.3.2 To prepare this standard synthetic ethanolic solution, the reagent grade ethanol must be analyzed to obtain the initial values o
48、f these constituents and then only add the appropriate amount of each constituent to obtain the total amount of each specified. NOTE: This standard synthetic ethanolic solution is not intended to simulate FGE within the current compositional limits defined by ASTM D4806,7 which have been recently lowered to include a maximum inorganic chloride concentration of 10 mg/L. 2.4 This test method also provides guidelines for perfo
