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用同一炉钢的铸件和锻件对比研究了在水介质中的应力腐蚀性能,结果表明,铸钢和锻钢应力腐蚀裂纹扩展的激活能相同,均为Q=5540cal/mol。且和氢渗透测出的表观扩散激活能Q=6010cal/mol相—致。无论是阳极极化还是阴极极化均使铸钢和锻钢的da/dt升高,但阴极极化更为明显,氢渗透测量表明,无论是阳极极化还是阴极极化,随电流增大,饱和氢渗透通量明显增加;极化对da/dt和氢渗透通量影响是相似的。 实验表明,试验温度对KIscc影响极小,但铸钢的KIscc明显比锻钢要高。氢渗透测试表明,锻钢的饱和氢渗透通量约比铸钢要大一倍,这就可解释KIscc的差异,这也和断口观察相一致,尽管断口形貌明显依赖开裂时的KI值,但在KIscc附近锻钢全是沿晶断口,而铸钢则以准解理为主。
The stress corrosion behavior in aqueous media was compared with castings and forgings of the same furnace. The results show that the activation energies of stress corrosion cracking propagation in cast steel and forged steel are the same, Q = 5540cal / mol. And the apparent diffusion activation energy measured by hydrogen permeation Q = 6010 cal / mol - induced. Both anodic polarization and cathodic polarization make the da / dt of cast steel and forged steel increase, but the cathodic polarization is more obvious. The measurement of hydrogen permeation shows that with either anodic polarization or cathodic polarization, the current increases , Saturated hydrogen permeation flux increased obviously; the effect of polarization on da / dt and hydrogen permeation flux were similar. Experiments show that the test temperature has little effect on KIscc, but the KIscc of cast steel is obviously higher than forged steel. Hydrogen permeation tests showed that the saturated hydrogen permeation flux forged steel was about twice as large as the cast steel, which explains the difference in KIscc, which is also consistent with the fracture observation, although the fracture morphology is significantly dependent on the KI value at cracking, However, forged steel in the vicinity of KIscc all along the crystal fracture, while the cast steel is mainly quasi-cleavage.