奥氏体不锈钢TP347H高温服役后磁化机制

摘要：针对超临界机组奥氏体不锈钢（TP347H）管高温运行后管壁出现的磁化现象进行研究。通过显微组织观察、扫描电镜及能谱分析,对其磁性产生原因进行分析。试验结果表明：强磁性区域可分为基体区（Ⅰ区）、大块析出相区（Ⅱ区）及氧化层区（Ⅲ区）,而弱磁性区域则仅存在基体区（Ⅰ区）与大块析出相区（Ⅱ区）,大块析出相主要含Ni元素,氧化层则为主要富含Cr、Fe、Ni、O,长期高温运行后Ni的大量析出并形成大块析出相区是导致奥氏体不锈钢TP347H发生明显磁化的主要原因。

Magnetization mechanism of austenitic stainless steel TP347H after high temperature service

The magnetization phenomenon of the supercritical unit austenitic stainless steel (TP347H) tube after high temperature operation was studied. The causes of magnetic generation were analyzed by microscopic observation, scanning electron microscopy and energy spectrum analysis. The experimental results show that the ferromagnetic region can be divided into matrix region (I region), large precipitate phase region (II region) and oxide layer region (III region), while weak magnetic region only has the matrix region (I region) and large precipitate phase region (II region), the large precipitate phase mainly contains Ni element, and the oxide layer is mainly rich in Cr, Fe, Ni, O. After long term high temperature operation, a large amount of Ni precipitates and forms a large precipitated phase zone, which is the main reason for obvious magnetization of austenitic stainless steel TP347H.