三段式控冷工艺对82B线材组织和性能的影响

提出风冷段三段式控制冷却工艺,即在冷却过程中加入模拟相变热的加热过程,以模拟热轧82B线材的实际风冷过程,分别研究相变前冷却速率、返温温度以及相变后冷却速率对82B线材组织和性能的影响。结果表明,返温温度和相变前后的冷却速率对珠光体片层间距都有影响,整个风冷过程的冷却速率对碳化物的析出均有影响,而马氏体的产生主要与返温温度和相变后的冷却速率相关;提高相变前后的冷却速率,都会提高线材的抗拉强度,加快相变前冷却速率以及降低相变后的冷却速率会使线材的面缩率提高。

Effect of three-stage controlled cooling on microstructure and performance of 82B wire rod

This paper proposes a three-stage controlled cooling process to simulate the actual air-cooling process of hot-rolled 82B wire rod. It studies the effect of the cooling rate before phase transition, the restoring temperature, and the cooling rate after phase transition on the structure and performance of 82B wire rod. It finds that that restoring temperature and cooling rates influence the pearlitic interlamellar spacing and during the whole process of controlled cooling, cooling rates have an effect on carbide exhalation. The production of martensite is mainly affected by restoring temperature and the cooling rate after phase transition. Increasing cooling rates before and after phase transition will enhance the tensile strength of the rod, and the surface shrinkage will be improved by accelerating the cooling rate before phase transition and reducing the cooling rate after phase transition.