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研究了超高强度钢Ⅲ型缺口试样在水介质中的应力腐蚀,并与动态充氢条件作了对比。结果表明,超高强度钢Ⅲ型试样在水介质中能产生应力腐蚀,而且裂纹沿着和原缺口面成45°的平面形核和扩展,获得沿晶断口。这些都和Ⅲ型试样动态充氢时氢致开裂的情况相同。水介质中加硫脲,能使Ⅲ型和Ⅰ型的应力腐蚀门槛值明显下降,如动态充氢,则使裂纹的孕育期和门槛值进一步下降,实验也表明,无论动态充氢还是应力腐蚀,Ⅲ型试样的门槛值均比Ⅰ型要高,这可用Ⅲ型和Ⅰ型的平衡氢浓度不同来解释。
The stress corrosion of ultrahigh strength steel Ⅲ notch specimens in aqueous media was studied and compared with the dynamic hydrogen charging conditions. The results show that the ultrahigh strength steel Ⅲ sample can produce stress corrosion in the aqueous medium, and the crack along the original notched plane and 45 ° plane nucleation and expansion, along the crystalline fracture. These are the same as in the case of Hydrogen-induced cracking of Type III samples during dynamic hydrogen charging. The addition of thiourea in aqueous medium can significantly reduce the stress corrosion thresholds of type III and type I, such as dynamic charge of hydrogen, further reducing the incubation period and threshold value of the crack. Experiments also show that both dynamic hydrogen charging and stress corrosion , Type III samples have higher thresholds than type I, which can be explained by the different equilibrium hydrogen concentrations for type III and type I.