正火冷却工艺对特厚低合金结构钢板组织性能的影响

The Effect of Normalizing + Cooling Process on Microstructure and Properties of Extra Heavy Low Carbon Structural Steel Plate

通过现场试验,发现厚钢板在经过正火处理后采用空冷、适当加速冷却、强冷三种冷却方式获得的组织性能各不相同。在没有特殊成分要求的低合金结构钢生产中,采用正火冷却工艺获得的力学性能能够完全满足标准要求。当钢的碳当量较低或受限时,空冷强度可能达不到标准要求,适当的加速冷却可以改善组织和性能,而强冷会加剧组织的不均匀性。本文结合某厚板厂现场试验情况,论述了正火冷却制度对组织性能的影响,阐述了正火+适当加速冷却工艺的合理性、可行性以及在特定条件下对正火工艺的辅助作用,对低碳当量、高强度正火大厚度钢板的开发具有重要意义。

In the site experiment, heavy steel plate shows different microstructure and properties in the mode of air cooling, rational accelerated cooling and intensified cooling after normalizing. During the production of low alloy structural steel without special composition requirements, the mechanical properties attained by normalizing ＋ cooling process fully satisfy the requirements of standards. In case of low or restraint carbon equivalent, the intensity of air cooling may not meet the standard requirements, but rational accelerated cooling can improve the microstructure and properties, intensified cooling shall deteriorate the homogeneity of microstructure. On the basis of site experiment at a heavy plate mill,the paper describes the effects of normalizing ＋ cooling process on microstructure and properties, the rationality and feasibility of normalizing ＋ rational accelerated cooling process,and believes that the process is favora- ble for normalizing process under specific conditions, which is of significance for the development of high strength nor-malizing heavy steel plate with low carbon equivalent.