论文部分内容阅读
研究了OCr 25Ni 5 Mo2,OCr 25Ni5Mo2N 和OCr 22NisMo3N 三种双相不锈钢由于中温(300～620℃)热处理而造成的脆化现象。结果表明,这三种双相不锈钢在此温区的脆化动力学曲线——等冲击功曲线都是两族相互连接的C 曲线:C 曲线族的交接处均在540—56o℃;脆化最快处发生在475℃左右。475℃脆化过程的表观激活能为160 kJ/mol,说明了475℃脆性发展的关键环节是铬原子的扩散。对试样断口形貌和精细组织的观察表明:双相钢在560℃以上处理时发生的脆化主要由碳氮化合物的析出所造成,而低温区的脆化则主要由α′相的析出所造成,碳氮有促进475℃脆性的作用。
The embrittlement caused by the heat treatment of OCr 25Ni 5 Mo2, OCr 25Ni5Mo2N and OCr 22NisMo3N three kinds of duplex stainless steel at medium temperature (300 ~ 620 ℃) was studied. The results show that the embrittlement kinetics curves of these three kinds of duplex stainless steel in this temperature range - the iso-impact energy curves are the C curves of the two families are connected: the intersection of the C-curve family are 540-56o ℃; embrittlement The fastest occurred at about 475 ℃. The apparent activation energy of the embrittlement at 475 ℃ is 160 kJ / mol, indicating that the key to the brittleness development at 475 ℃ is the diffusion of chromium atoms. The observation of the fracture morphology and fine structure of the specimen showed that the embrittlement occurred when the duplex steel was treated at 560 ℃ or above, which was mainly caused by the precipitation of carbon and nitrogen compounds, while the embrittlement in the low temperature region was mainly caused by the precipitation of α ’phase As a result, carbon and nitrogen promote the brittleness of 475 ℃.