Standard practices forDetecting susceptibility to intergranular attack in austenitic stainless steels奧氏體不銹鋼晶間腐蝕敏感性標準實驗1.scope1.應用範圍these practices cover the following five tests:1.2 這些實驗包括下列五類：1.1.1 parctics A- oxalic acid etch test for classification of etch structures of austenitic stainless steels(section 3 to 7, inclusive)1.1.1實驗A——奧氏體不銹鋼草酸浸蝕試驗後的浸蝕組織分類（包括3－7部分1.2 the following factors govern the application of these practices:1.2以下因素主導著這類實驗：1.2.1 susceptibility to intergranular attack associated with the precipitation of chromium carbides is readily detected in all six tests.1.2.1晶間腐蝕敏感性同碳鉻化合物的快速析出1.2.2 sigma phase in wrought chromium-nickel-molybdenum steels. Which may or may not be visible in the microstructure, canresult in high corrosion rates only in nitric acid.1.2.2在鉻鎳鉬鋼中可見的和不可見的sigma相，只有在硝酸中才會快速腐蝕。
1.2.3 sigma phase in titanium or columbium stabilized alloys and cast molybdenum-bearing stainless alloys, which may or may not be visible in the microstructure, can result in high corrosion rates in both the nitric acid and ferric sulfate-sulfuric acid solutions.1.2.3在鈦合金或穩定化合金和鑄造鉬柱狀晶中的sigma相，不管在其顯微組織中可見不可見都會在硝酸和硫化鐵溶液中引起嚴重腐蝕。
1.3 the oxalic acid etch test is a rapid method of identifying, by simple etching, those specimens of certain stainless steel grades that are essentially free of susceptibility to intergranular attack associated with chromium carbide precipitates. These specimens will have low corrosion rates in certain corrosion tests and therefore can be eliminated (screened) from testing as ―acceptable.‖1.3草酸浸蝕試驗是一個快速方法用來使這些本質上晶間腐蝕不敏感的不銹鋼試樣快速析出碳鉻化合物。
1.7 only these stainless steel grades are listed in table one for which data on the application of the oxalic acid etch testand on their performance in various quantitative evaluation tests are available.1.7在表一中列出哪些適合用草酸進行浸蝕試驗及各種數量測試下的性能是有效的。
Practice A oxalic acid etch test for classification of etch structures of austenitic stainless steels 2實驗A——奧氏體不銹鋼草酸浸蝕試驗後的浸蝕組織分類3.1 the oxalic acid etch test is used for acceptance of material but not for rejection of material. This may be used in connection with other evaluation tests to provide a rapid method for identifying those specimens that are certain to be free of susceptibility to rapid intergranular attack in these other tests. Such specimens have low corrosion rates in the various hot acid tests, requiring from 4 to 20 h of exposure. These specimens are identified by means of their etch structures, which are classified according to the following criteria：3.1草酸浸蝕法晶間腐蝕試驗一般用來作為材料的評價，不作為材料的判廢標準。
这方法一般为其它评价方法提供一个快速途径来鉴定实验试样在各种测试中是否具有晶间腐蚀敏感性。
这些在各种热酸试验中腐蚀率都很低的试样，需要承受4至20小时的试验。
通过对这些腐蚀试样的腐蚀结构来进行评判。
相应的定级根据下列标准：3.2 the oxalic acid etch test may be used to screen speciments intended for testing in practice B--Ferric Sulfate-Sulfuric Acid Test, practice C—nitric acid test, practice E—copper-copper sulfate-16% sulfuric acid test, and practice F—copper-copper sulfate-50% sulfuric acid test.3.2 草酸浸蚀试验是代替试验程序B——硫化铁和硫酸溶液试验，程序C——硝酸试验，程序F——铜和硫化铜及16%硫酸铜溶液试验，用来甄别试样。
3.2.1 each practice contains a table showing which classifications of etch structures on a given stainless steel grade are equivalent to acceptable, or possibly nonacceptable performance in that particular test. Specimens having acceptable etch structures need not be subjected to the hot acid test. specimens having nonacceptable etch structures must be tested in the specified hot acid solution.3.2.1 每个试验程序都包括一个表格，这个表格显示给定试验不锈钢的浸蚀组织中哪类同等级别下可以被接受，或者在这特殊的实验后哪些性能可能不被接受。
试样拥有可以被接爱的显微组织不必服从热酸试验。
试样拥有不接爱的显微组织必须得在批定热酸溶液下进行试验。
3.3 the grades of stainless steels and the hot acid tests forwhich the oxalic acid etch test is applicable are listed in table 2.3.3 不锈钢等级和哪类钢需要进行热草酸酸测试见表2。
3.4 extra-low-carbon grades, and stabilized grades, such as 304L,316L,317L,321, and 347, are tested after sensitizing heat treatments at 650 ℃to 675℃,which is the range of maximum carbide precipitation. These sensitizing treatments must be applied before the specimens are submitted to the oxalic acid etch test. The most commonly used sensitizing treatment is 1h at 675℃.3.4 对于超低碳级的和稳定化级的不锈钢，如304L,316L,317L,321和347这些材料应该在其最大碳化物析出温度650 ℃到675℃区域进行敏化处理后再进行晶间腐蚀试验。
敏化处理应该在草酸浸蚀试验前进行，一般用675℃保温一小时的处理方法。
4. apparatus4．仪器装置4.1 source of direct current-battery, generator, or rectifier capable of supplying about 15 V and 20 A.4.1 直流电源——同时可以有能力提供15伏和20安的电池、发电机或者变压器。
4.2 ammeter-range 0 to 30 A (note 1)4.2 电流表（安培计）——范围是0至30安培（注1）4.3 variable resistance (note 1)4.3 可变电阻（注1）4.4 cathode-A cylindrical piece of stainless steel or, preferably, a 1-qt (0.946-L) stainless steel beaker.4.4 阴极——一个圆柱形的不锈钢棒，最好是一个一加仑的不锈钢烧杯。