1500MPa级40CrNi3MoV钢的氢脆敏感性

HYDROGEN EMBRITTLEMENT SUSCEPTIBILITY OF 1500 MPa GRADE 40CrNi3MoV STEELS

通过慢应变速率拉伸实验研究了Si含量分别为0.25%和1.16%的1500 MPa级40CrNi3MoV钢的氢脆敏感性,即充氢后缺口试样抗拉强度下降率,冲击实验用来测试1 mA/cm^2电流密度下充氢后试样的断裂韧性值,分析氢致裂纹的扩展方式.结果表明,由于Si抑制回火过程中碳化物的形核和长大,高Si含量的40CrNi3MoV钢中回火析出的碳化物被细化且弥散分布,作为氢陷阱使氢分布均匀,抑制了氢向裂纹尖端扩散,高Si含量的40CrNi3MoV钢的氢脆敏感性较低.

Hydrogen embrittlement susceptibilities of 1500 MPa grade 40CrNi3MoV steels with 0.25%Si and 1.16%Si were investigated by means notch tensile strength and the compact specimens the hydrogen embrittlement susceptibility and to of slow strain rate tensile test. The reduction of after hydrogen charging were used to characterize investigate hydrogen-induced crack propagation, respectively. Results show that the 40CrNi3MoV steel with higher Si content was less susceptible to hydrogen embrittlement than that with the lower Si content, the reason is that the carbides in the former steel are refined, which may act as the sites for hydrogen trapping and prevent hydrogen from diffusing into crack tip.