316L不锈钢应力腐蚀慢应变速率拉伸试验  

Discussion on the stress corrosion of 316L stainless steel by slow strain rate tension test

作　　者：王硕[1] 陶然[1] 

机构地区：[1]国家建筑钢材质量监督检验中心,北京100088

出　　处：《物理测试》2016年第2期12-15,共4页Physics Examination and Testing

摘　　要：就316L不锈钢在不同腐蚀环境下的慢拉伸力学性能进行了试验研究。所有试验在恒定应变速率2.4×10-7/s和恒定温度80℃条件下进行,高压釜中为5%Na Cl水溶液,并分别充入CO2和H2S气体。通过改变Cl-的浓度研究Cl-在慢拉伸试验条件下对316L不锈钢的力学性能的影响。试验结果表明,Cl-对316L不锈钢的拉伸力学性能有明显影响,随着Cl-浓度的增加,316L不锈钢的抗拉强度逐渐降低;即Cl-可能是导致316L不锈钢慢拉伸应力腐蚀的关键因素。对316L不锈钢慢拉伸样品断口的SEM微观分析表明,在Cl-的作用下其断裂特性由韧性断裂逐渐转变为脆性断裂,即断口形貌在无Cl-和Cl-浓度较低时有明显的韧窝,为穿晶断裂;而随着Cl-浓度增加,断口形貌为解理性断裂,为沿晶断裂。The mechanical property of 316 L stainless steel under different corrosion environments was studied by slow strain test. All tests were conducted at constant strain rate（2.4×10^-7/s） and temperature（80 ℃）. The high pressure kettle contained 5% Na Cl aqueous solution. CO2 and H2S were filled,respectively. The effect of Cl-on the mechanical property of 316 L stainless steel under slow strain rate conditions was investigated by varying the concentration of Cl-. The test results indicated that the Cl-concentration had significant influence on the tensile mechanical property of 316 L stainless steel. The tensile strength of 316 L stainless steel gradually decreased with the increase of Cl-concentration. In other words,Cl-was possible the key factor to cause stress corrosion of 316 L stainless steel in slow strain rate tension test.The fracture morphology of 316 L stainless steel sample in slow strain rate test was analyzed by scanning electron microscope. It was found that the fracture characteristics gradually changed from ductile fracture to brittle fracture in presence of Cl-. The fracture morphology exhibited an obvious dimple pattern（i.e.,transcrystalline fracture） when there was no Cl-or the concentration of Cl-was low. However,with the increase of Cl-concentration,the fracture morphology changed to cleavage fracture（i.e.,intercrystalline fracture）.

关 键 词：316L 慢应变速率拉伸 Cl-浓度 抗拉强度 解理性断裂 

分 类 号：TG142.71[一般工业技术—材料科学与工程]