析出相对马氏体时效钢氢扩散系数的影响

Effect of precipitate on hydrogen diffusion coefficient of TM210 maraging steel

采用TEM和双电解池氢渗透法研究了TM210马氏体时效钢不同时效时间的析出相及其对氢扩散性能的影响。结果表明,马氏体时效钢在465℃下分别时效3 h、60 h和100 h后,都仅生成Ni3Ti析出相,长度分别为约10.4、26.8、36.8 nm,同时析出相线度与时效时间符合关系r珋3=375t。晶体结构为简单六方,点阵常数a=0.5101 nm,c=0.8304 nm。随着时效时间的延长,析出相长大,数量减少,单位体积数量分别为32、9.26和6.23(1022/m3),但体积分数增加。3种时效条件下的氢扩散系数分别为3.34、5.68和6.52(10-9cm2/s)。这些结果表明析出相作为氢陷阱能够影响氢在钢中的扩散,析出相数量越多,氢扩散系数越小。

The precipitate and its influence on hydrogen diffusion property in a TM210 maraing steel age-treated for different time were studied by transmission electron microscopy and electrochemical permeation technique.The results indiciate that the precipitates are all Ni3 Ti phase after aging at 465 ℃ for 3,60 and 100 h,respectively,and the corresponding length of the precipitates are 10.4,26.8 and36.8 nm,respectively.Moreover,the relationship between the length of the precipitate(r珋) and the aging time(t) can be presented as r珋3= 375 t.The crystal structure of the precipitate,Ni3 Ti,is simple hexagonal,and the lattice constants of a and c are 0.5101 nm and0.8304 nm.As the size of the precipitate increased with the aging time,the number of per unit volume of the precipitate decreased with the aging time,which are 32,9.26 and 6.23(1022/m3),respectively,and the measured hydrogen diffusion coefficients decreased with the aging time,which are 3.34,5.68 and 6.52(10-9cm2/s),respectively.The precipitate can be served as hydrogen trap,and hence arrested the hydrogen diffusion in the crystal lattice of steel matrix.