工艺参数对耐蚀钢12CuCrNiV组织与性能的影响

采用热力模拟试验机、光学显微镜、显微硬度计研究了耐蚀钢12CuCrNiV在不同冷却速率下的连续冷却组织转变规律,并绘制其CCT曲线,同时研究了形变温度和冷却速度对耐蚀钢热变形后的组织和硬度的影响规律。结果表明:连续冷却转变情况下,耐腐蚀钢在冷速小于15℃/s时,有铁素体转变;冷速小于1℃/s时,有珠光体转变;冷速在0.5~20℃/s之间时,有贝氏体转变。控制冷速在5~15℃/s可得到铁素体和贝氏体复相组织。随变形温度的降低,试验钢形变过程中形变诱导铁素体相变现象显著,且伴随有M/A岛生成;随冷却速度的增高,形变诱导相变现象减弱,M/A岛数量减少。与连续冷却试验相比较,形变诱导析出现象明显,其硬度增量为40~50HV,形变可使试验钢的析出向更高冷速移动。

Influence of process parameters on microstructure and performance of corrosion resisted steel 12CuCrNiV

Continuous cooling transformation curves were drawn and microstructure evolution behavior was investigated for corrosion resisted steel 12CuCrNiV with thermal- mechanical simulation machine, optical microscope and micro- hardness tester. And the influences of cooling rate and deformation temperature on the microstructure and hardness of the steel after thermal- mechanical deformation also were discussed. The results show that there is ferrite transformation with cooling rate of less than 15??/s, there is pearlite transformation with cooling rate of less than 1??/s and there is bainite transformation with cooling rate of 0.520??/s in the corrosion resisted steel. An advantageous complex phase microstructure of ferrite and bainite can be achieved when the cooling rate is between 5??/s and 15??/s. With the decrease of deformation temperature, the phenomenon of strain induced ferrite transformation is obvious and M/A island forms during deformation of the steel. However, with the increase of cooling rate, the phenomenon of strain induced ferrite transformation weakens and the number of M/A islands reduces during deformation of the steel. Compared with the results of continuous cooling transformation, the phenomenon of strain induced precipitation is obvious, its increase of hardness is 4050 HV and deformation can make precipitation of tested steel move toward higher cooling rate.