12Cr2MoWVTiB钢在高温长时间应力作用下显微组织的转变

An Investigation of Microstructural Changes of 12Cr2MoWVTiB Steel under Long Term High Temperature-Stress

摘要: 本文研究12C_R2M_o WVTIB钢在620℃、650℃、670℃下持久强度试验后的断口形貌和显微组织,发现不论在持久强度曲线转折之前,还是转折之后,都是穿晶韧窝状断口。
钢中碳化物在试验中有不断变化,因而导致固溶体中合金元素贫化,使固溶体硬度下降,并发生再结晶。这些就构成12C_R2M_oWVTiB钢的持久强度发生转折的主要成因。

Abstract: The fracture surface and microstructure of 12Cr2MoWVTiB steel are investigated after a series of creep rupture tests at 620,650,670 degrees centigrade respectively.It is found that all the specimens are ruptured in the form of transcrystalline ductile fracture.
The carbides change continuously during the test,resulting in the poorness of alloy element in solid solution,decrease in the hardness of solid solution,and recrystallization.These are the main reasons why the creep rupture strength of 12Cr2MoWVTiB steel inflects.