阴极极化对高强钢焊接件应力腐蚀敏感性的影响

目的研究不同极化电位下高强钢焊接件在海水中的应力腐蚀敏感性。方法采用慢应变速率试验(SSRT)和电化学阻抗技术来判定不同极化电位条件下高强钢焊接件在海洋环境中应力腐蚀敏感性的大小,利用扫描电镜和三维视频测试技术观察试样断裂处的颈缩情况和断裂方式。结果在E corr~-0.9 V电位区间内,高强钢焊接件在海水中没有明显的应力腐蚀敏感性;在-1.1~-1.2 V电位区间内,焊接件断口出现脆性断裂特征,力学性能下降明显,具有很强的应力腐蚀敏感性。结论阴极极化对高强钢焊接件在海水中的应力腐蚀敏感性影响显著。

Effect of Cathodic Polarization on Stress Corrosion Cracking Susceptibility of Weld High Strength Low Alloy Steel in Seawater

Objective To study the stress corrosion cracking behaviors of high-strength low-alloy steel in seawater under different cathodic polarization potentials. Methods Slow strain rate tests （SSRT）,electrochemical impedance spectroscopy（EIS）were used to study the effect of cathodic polarization on stress corrosion cracking susceptibility,scanning electron microscopy （SEM） and Microscopic three-dimensional screen research tools were used to study the necking and fracture surface of samples. Results There is no stress corrosion cracking susceptibility under the Ecor~-0.9 V potential,and high stress corrosion cracking susceptibility under the-1.1~-1.2 Vpotential. Conclusion Cathodic polarization showed significant influence on the stress corrosion cracking behavior of weld high strength low alloy steel in seawater.