1、Designation: G146 01 (Reapproved 2013)Standard Practice forEvaluation of Disbonding of Bimetallic Stainless Alloy/SteelPlate for Use in High-Pressure, High-Temperature RefineryHydrogen Service1This standard is issued under the fixed designation G146; the number immediately following the designation
2、indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers a procedure for t
3、he evaluation ofdisbonding of bimetallic stainless alloy/steel plate for use inrefinery high-pressure/high-temperature (HP/HT) gaseous hy-drogen service. It includes procedures to (1) produce suitablelaboratory test specimens, (2) obtain hydrogen charging con-ditions in the laboratory that are simil
4、ar to those found inrefinery HP/HT hydrogen gas service for evaluation of bime-tallic specimens exposed to these environments, and (3)perform analysis of the test data. The purpose of this practiceis to allow for comparison of data among test laboratories onthe resistance of bimetallic stainless all
5、oy/steels to hydrogen-induced disbonding (HID).1.2 This practice applies primarily to bimetallic productsfabricated by weld overlay of stainless alloy onto a steelsubstrate. Most of the information developed using this prac-tice has been obtained for such materials. The proceduresdescribed herein, m
6、ay also be appropriate for evaluation of hotroll bonded, explosive bonded, or other suitable processes forapplying stainless alloys on steel substrates. However, due tothe broad range of possible materials, test conditions, andvariations in test procedures, it is up to the user of this practiceto de
7、termine the suitability and applicability of these proce-dures for evaluation of such materials.1.3 This practice is intended to be applicable for evaluationof materials for service conditions involving severe hydrogencharging which may produce HID as shown in Fig. 1 forstainless steel weld overlay
8、on steel equipment (see Refs 1 and2inAppendix X1). However, it should be noted that thispractice may not be appropriate for forms of bimetallicconstruction or service conditions which have not been ob-served to cause HID in service.1.4 Additional information regarding the evaluation of bi-metallic s
9、tainless alloy/steel plate for HID, test methodologies,and the effects of test conditions, materials, and weldingvariables, and inspection techniques is given in Appendix X1.1.5 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.
10、6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. See Section 6 fo
11、radditional safety information.2. Referenced Documents2.1 ASTM Standards:2G111 Guide for Corrosion Tests in High Temperature orHigh Pressure Environment, or BothE3 Guide for Preparation of Metallographic Specimens2.2 ASME Standard:Boiler and Pressure Vessel Code Section V, Article 5, Tech-nique Two3
12、3. Terminology3.1 Definitions:3.1.1 HIDa delamination of a stainless alloy surface layerfrom its steel substrate produced by exposure of the material toa hydrogen environment.3.1.1.1 DiscussionThis phenomenon can occur in inter-nally stainless alloy lined steel equipment by the accumulationof molecu
13、lar hydrogen in the region of the metallurgical bondat the interface between the steel and stainless alloy surfacelayer produced by exposure to service conditions involvingHP/HT hydrogen in the refinery hydroprocessing.1This practice is under the jurisdiction of ASTM Committee G01 on Corrosionof Met
14、als and is the direct responsibility of Subcommittee G01.05 on LaboratoryCorrosion Tests.Current edition approved May 1, 2013. Published July 2013. Originally approvedin 1996. Last previous edition in 2007 as G14601 (2007). DOI: 10.1520/G0146-01R13.2For referenced ASTM standards, visit the ASTM webs
15、ite, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American Society of Mechanical Engineers (ASME), ASMEInternational Headquarters, Three Park Ave.
16、, New York, NY 10016-5990, http:/www.asme.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14. Summary of Practice4.1 Stainless alloy/steel specimens are exposed to a gaseoushydrogen containing environment at HP/HT conditions forsuf
17、ficient time to produce hydrogen charging in the material.Following exposure, the specimens are cooled to ambienttemperature at a controlled rate. The specimens are then held atroom temperature for a designated period to allow for thedevelopment of HID between the stainless alloy surface layerand th
18、e steel. Following the hold period, the specimens areevaluated for HID at this interface using straight beam ultra-sonic methods with metallographic examination to confirm anyHID found. The size and distribution of the disbonded re-gion(s) are then characterized by this practice. Single ormultiple h
19、ydrogen exposure/cooling cycles can be conductedand varying exposure conditions and cooling rates can beincorporated into this evaluation to provide assessment of thedisbonding characteristics of materials and service conditionused for refinery process equipment containing HP/HT hydro-gen containing
20、 environments.5. Significance and Use5.1 This practice provides an indication of the resistance orsusceptibility, or both, to HID of a metallurgically bondedstainless alloy surface layer on a steel substrate due to exposureto hydrogen-containing gaseous environments under HP/HTconditions. This pract
21、ice is applicable over a broad range ofpressures, temperatures, cooling rates, and gaseous hydrogenenvironments where HID could be a significant problem.Theseprocedures can be used to assess the effects of materialcomposition, processing methods, fabrication techniques, andheat treatment as well as
22、the effects of hydrogen partialpressure, service temperature, and cooling rate. The HIDproduced by these procedures may not correlate directly withservice experience for particular applications.Additionally, thispractice does not address the evaluation of high-temperaturehydrogen attack in the steel
23、 substrate. Typically, longer expo-sure times at the test conditions must be utilized to allow forthe resistance to decarburization, internal blistering orcracking, or both, to be evaluated.6. Apparatus6.1 Because this practice is intended to be conducted at highpressures and high temperatures, the
24、apparatus must be con-structed to safely contain the test environment while beingresistant to the cumulative embrittling effects of hydrogen.Secondly, the test apparatus must be capable of allowing (1)introduction of the test gas, (2) removal of air from the test cell,(3) uniform heating of the test
25、 specimens, and (4) cooling ofthe specimens at controlled rates.6.2 There are many types of test cell configurations whichcan be used to conduct evaluations of HID. This practice doesnot recommend or endorse any particular test cell design. Fig.2 shows a schematic representation of a typical test ce
26、lldesigned to conduct HID tests in HP/HT gaseous hydrogenenvironments. Other designs may also provide acceptableperformance. However, the typical components should includethe following:6.2.1 Metal Test CellThe test cell should be constructedfrom materials which have been proven to have high resistan
27、ceto hydrogen embrittlement and high-temperature hydrogenattack under the anticipated test conditions. Materials with lowresistance to these phenomena should be avoided. Typical testcells for high-pressure hydrogen testing are constructed fromstainless steel (UNS S31600 or S34700) or nickel alloys (
28、UNSN10276 or N06625) in the solution annealed condition. Steelvessels with stainless alloy exposed surfaces may also besuitable.NOTE 1Open symbolsno disbonding reported. Filled symbolsdisbonding reported.FIG. 1 Conditions of Hydrogen Partial Pressure and Temperaturewith Demonstrated Susceptibility t
29、o Hydrogen Disbonding in Re-finery High-Pressure Hydrogen ServiceFIG. 2 Typical Test CellG146 01 (2013)26.2.2 Closure and SealTo facilitate operation of the testcell, the closure should provide for rapid opening and closingof the test cell while retaining reliable sealing capabilities forhydrogen. T
30、his can include either metallic or nonmetallicmaterials with high resistance to thermal degradation andhydrogen attack.6.2.3 Gas Port(s)The gas port should be designed topromote flow and circulation of the gaseous test environments,inert gas purging, and evacuation as required to produce theintended
31、 test environment. Usually two ports are used so thatseparate flow-through capabilities are attained to facilitatethese functions.6.2.4 Electrical Feed-ThroughsHigh-temperature condi-tions are required in this practice. It is usually advantageous toutilize an internal heater to heat just the test sp
32、ecimens and thegaseous environment in the immediate vicinity of the speci-men. Therefore, feed-throughs are usually needed to makeelectrical contact with an internal resistance or inductionheater. These feed-throughs must also provide (1) electricalisolation from the test cell and internal fixtures
33、and (2)maintain a seal to prevent leakage of the test environment. Ifexternal heaters are used, no electric feed-throughs are re-quired.6.2.5 Electric Resistance or Induction Heater(s)Eitherinternal or external heaters can be used to obtain elevatedtemperature. For lower temperatures (300C), an inte
34、rnal heater is commonly used toheat only the test specimen and the gaseous environment in thevicinity of the test specimens to limit power requirements andproblems with high-temperature sealing and pressure contain-ment.7. Reagents7.1 Purity of ReagentsLow oxygen gases (50Distribution RankingADistri
35、bution1 isolated disbonded regions2 interlinking disbonded regions3 disbonding at weld pass overlaps4 disbonding at joint with side overlay5 other (please describe)AMore than one category may be indicated.12.17 If the effects of multiple exposure cycles are beingevaluated, the sample may be held at
36、24 6 2.5C for a periodof 48 h and then ultrasonically evaluated. If no hydrogendisbonding or crack growth is detected ultrasonically after the48-h hold period, then the subsequent hydrogen pressure/temperature cycle may be initiated. If disbonding or crackgrowth is observed after 48 h, then either (
37、1) the test can bediscontinued or (2) the full seven-day hold period must bemaintained prior to the next hydrogen/temperature cycle.12.18 Upon completion of testing, the test specimen shall besectioned to expose the stainless alloy surface layer, stainlessalloy/steel interface, and the steel substra
38、te. If no disbonding isfound with the ultrasonic examination, then the section shall bemade through the center of the specimen. If the ultrasonicinspection detects HID, the section shall be positioned throughthe region of maximum disbonding.12.19 The specimen shall be metallographically ground andpo
39、lished using procedures given in Practice E3. The edges maybe beveled and the half of the section opposite the stainlessalloy layer may be removed to facilitate handling duringmetallographic preparation.12.20 The stainless alloy/steel interface shall be examined.A representative, unetched micrograph
40、 shall be taken at 200.Following the unetched examination, the specimen shall beetched to reveal the structure of the stainless alloy surface layerand the microstructure structure of the steel substrate at thisinterface. Representative micrographs of stainless alloy etchedand steel etched sections s
41、hall be taken at 200. From themetallographic examination of the sections, the location andnature of the disbonding, if present, shall be described relativeto the stainless steel surface layer, stainless alloy/steelinterface, and steel substrate.13. Report13.1 Report the following information for all
42、 hydrogendisbonding tests:13.1.1 Test Conditions:13.1.1.1 Test temperature,13.1.1.2 Hydrogen gas pressure at the test temperature,13.1.1.3 Hold time at test conditions,13.1.1.4 The cooling rate from the test temperature range toambient temperature,13.1.1.5 Number of hydrogen pressure/temperature cyc
43、les,13.1.1.6 Post-test holding time at 24 6 2.5C prior toultrasonic inspection, and13.1.1.7 Hold time at 24 6 2.5C between temperaturecycles (if applicable).13.1.2 Ultrasonic Inspections:13.1.2.1 Number, size, and distribution of disbonded re-gions at stainless alloy/steel interface for both pre-tes
44、t inspec-tion and post-test inspection, and13.1.2.2 Disbonding ranking for post-test examination usingalphanumeric coding provided in Section 12.13.1.3 Metallographic Examination Following Testing:G146 01 (2013)513.1.3.1 Representative micrographs of sections acrossstainless alloy/steel interface at
45、 200 which shall include:(1) Unetched,(2) Stainless alloy etched, and(3) Steel substrate etched.13.1.3.2 Description of the location and nature of HIDrelative to stainless alloy surface layer, stainless alloy/steelinterface, and steel substrate.13.1.4 Specimen characterization including orientation,
46、type, size, number of specimens tested, and surface prepara-tion.13.1.5 Characterization of Material:13.1.5.1 The bulk chemical composition of both the stain-less alloy layer and steel substrate shall be provided includingthe carbon, sulfur, and phosphorus and any carbide-formingelements such as tit
47、anium, niobium (columbium) in the stain-less alloy and chromium, titanium, vanadium, and molybde-num in the steel substrate.13.1.5.2 A description of the application method of thestainless alloy shall be provided. The details of this descriptionshould be covered in product or purchase specifications
48、 and arenot covered in this practice.14. Keywords14.1 autoclave; disbonding; high pressure; high tempera-ture; hydrogen; hydroprocessing; metallography; refining; ul-trasonic testingAPPENDIX(Nonmandatory Information)X1. PERTINENT LITERATUREX1.1 The following list of references is provided for addi-t
49、ional information regarding this evaluation of bimetallicstainless alloy/steel plate for HID, test methodologies, and theeffects of test conditions, materials and welding variables, andinspection techniques.(1) Cayard, M. S., Kane, R. D., and Stevens, C. E.,“ Evaluation ofHydrogen Disbonding of Stainless Steel Cladding for High Tempera-ture Hydrogen Service,” Paper No. 518, CORROSION/94, NACEInternational, March 1994.(2) Minutes of Refining Subcommittee on Corrosion and Research,Attachment IV, American Petroleum Institute, Midyear RefiningMeeting, New Orleans, LA
