渗硼对钢材机械性能的影响

本文研究了固体渗硼对钢材(20CrMo,45,T8及 GCr15)机械性能的影响。渗硼后得到Fe_2B或 FeB Fe_2B渗硼层。本研究进行了渗硼试样的拉伸、多次冲击以及旋转弯曲疲劳试验,并与未渗硼试样进行比较。其结果为:(1)对于低碳合金钢(20CrNiMo、20CrMo),渗碳对拉伸强度及多次冲击抗力的影响很小,韧性有所下降;渗硼后进行淬火及低温回火处理,使强度及韧性均下降。(2)对中碳结构钢(45),渗硼对拉伸强度及多冲抗力影响也很小,韧性也有所下降。渗硼后经淬火高温回火,刚拉伸强度有所增加,塑性稍有下降。若渗硼后再经淬火及低温回火,拉伸强度及塑性均有显著降低。45钢渗硼后,疲劳强度提高,单相时提高更多。(3)对于高碳工具钢T8及滚动轴承钢GCr15,渗硼后拉伸强度及塑性均下降,后者下降幅度更大;多冲抗力也有所下降。

THE INFLUENCE OF BORONIZATION ON MECHANICAL PROPERTIES OF STEELS

In this paper the influence of pack boronization on mechanical properties of steels (20CrMo, Seel-45, T8 and GCrlS) was investigated. After boronizing boride layer of Fe2B or FeB Fe2B was obtained. In the present study, tensile and repeated impact as well as rotated-bending fatigue tests were carried out. As compared to the nonboronizing samples, the test results are as follows. 1. For low carbon alloy steel (20CrNiMo) and medium carbon structure steel (steel 45) boronization has only a little effect on the tensile strength and resistance to repeated impact, but reduces the ductility. Boronization followed by quenching and low-temperature tempering reduces both tensile strength and ductility, 2. For medium carbon structure steel (steel 45) boronization followed by quenching and high temperature tempering the tensile strength increases slightly the ductility and reduces somewhat. 3. For high carbon steel (T8) and bearing steel (GCr15) bornization reduces significantly both the tensile strength and ductility, at the same time reduces the resistance to repeated impact; 4. For steel 45 boronization increases the endurance limit.