中文摘要：

利用热拉伸模拟方法研究了稀土对22Cr型双相不锈钢高温塑性的影响，并结合微观结构分析讨论了稀土的作用机制。结果表明： 含量为0.042%的稀土可改善试验钢的高温塑性，扩大热加工安全区间近90 ℃。一方面，稀土使700~800 ℃范围的塑性低凹区基本消除，断口韧窝大且深并少见解理平台，这与其可在一定程度上抑制有害相σ相在δ/γ相界处形核有关；另一方面，稀土可改善两相的分布和形态，减少硬相奥氏体的尖角，从而抑制高温区塑性的迅速降低。

英文摘要：

The effect of RE on hot ductility of 22Cr type duplex stainless steel was investigated throughthermalmechanical simulation in combination of mi crostructure observations. The results showed that the hot ductility of the test steel with 0. 042% RE could be improved significantly, especially at the temperature range of 700 900 ℃ and more than 1100 ℃. On one hand, the ductility drop of the steel with RE, between 700 and 800 ℃, was almost eliminated, and the dimples on the fracture surface was bigger and deeper and few cleavage steps could be observed. This results might be related to the inhibitory effect of RE on the detrimental σ located on the interface of austenite and ferrite. On the other hand, RE could improve the shape and distribution of both phase, in particular, the harder austenite with sharp angle was less due to RE addition , which was responsible for slowdown of the hot ductility at the higher temperature range （more than 1100 ℃ ）