耐酸性高Mn奥氏体钢的实验研究

Experiment research of high Mn austenitic steel with acid resistance

为适应特殊油气开采环境的复杂工况条件,提高设备的使用寿命和安全性,降低开采成本,不同于常规管线钢低C低Mn的合金设计思路,采用高C高Mn成分体系获得了综合性能优异的新型耐酸性奥氏体钢.通过拉伸实验、冲击试验以及氢致开裂实验等方法对其综合性能进行研究,并利用光学显微镜、扫描电镜、透射电镜等手段对高Mn奥氏体钢的组织进行了观察分析.研究结果表明:实验钢抗拉强度达到1 153 MPa,屈强比仅为0.46,伸长率高达50%,-40℃冲击功达到123 J,同时A溶液条件下经96 h浸泡未发现氢鼓泡及裂纹.实验钢显微组织为单相奥氏体组织,组织中存在大量位错、层错以及孪晶.与常规管线钢相比较,实验钢具有低屈强比、高均匀塑性变形的优点.此外,奥氏体组织的溶氢能力极强,本实验钢具有优良的抗氢致开裂腐蚀性能.

A new acid corrosion resistance austenitic steel with high carbon and manganese content differing from regular pipeline steel was obtained to improve the service life of equipment and reduce the cost. Properties of austenitic steel were researched by tensile test, impact test and HIC test. And the mierostructure of the austenitie steel was studied by OM, SEM and TEM. The tensile strength of the steel reached 1 153 MPa and the yield ratio was only 0.46. The elongation reached as high as 50% and the impact energy reached 123 J at -40 ℃. HIC test showed that hydrogen bubble and cracks were not found in A solution for 96 hours. Microstructure of the test steel was a single phase austenite, and there were many dislocations, faults and twins. The experimental steel showed the advantages of low yield ratio and high uniform plastic deformation comparing with conventional pipeline steel. Austenitic dissolved hydrogen capacity is much higher than other groups, therefore the experimental steel had good corrosion resistance to hydrogen induced crack.