回火工艺对生态建筑用钢组织与力学性能的影响

Effects of Tempering Process on Microstructure and Mechanical Properties of Steel for Ecological Building

研究了脉冲电流回和传统回火对脉冲淬火态和传统淬火态建筑用钢组织与性能的影响,分析了脉冲电流的作用机制。结果表明,不同时间脉冲电流回火时间后建筑用钢的抗拉强度和硬度都相较于脉冲淬火态和传统淬火态有所降低,而断后伸长率有所升高;随着脉冲电流回火时间的延长,脉冲淬火态和传统淬火态试样的硬度和抗拉强度逐渐降低,而断后伸长率逐渐升高。脉冲电流回火可以在不降低硬度和强度的前提下提高试样的断后伸长率,而传统回火是以降低硬度和强度来实现断后伸长率的提高,这主要是因为脉冲电流回火在消除残余应力的同时,淬火马氏体分解较少且析出的细小碳化物可以起到弥散强化的作用,而传统回火态试样的淬火马氏体分解更为充分且碳化物有所长大。

The effects of pulse current tempering and traditional tempering on the microstructure and mechanical properties of the pulse quenched and traditional quenched building steels were studied, and the mechanism of pulse current was analyzed. The results show that, the tensile strength and hardness of steel after pulse current tempered at different time are lower than those of pulse quenched and traditional quenched steels, while the elongation increases. With the tempering time of pulse current increasing, the hardness and tensile strength of the pulse quenched and traditional quenched specimens decrease,and the elongation increases gradually. Pulse current tempering can improve the elongation without reducing the hardness and strength, while the traditional tempering reduces the hardness and strength and improves the elongation, this is mainly because pulse current tempering can eliminate residual stress while a little of quenching martensitie decomposes, and the fine precipitated carbide can play the role of dispersion strengthening, but the quenched martensite decomposition of the traditional tempered samples is more complete and the carbide grows.