1000MPa级高强钢焊接件的氢脆敏感性研究

发布时间：2018-07-11 17:47

本文选题：高强钢 + 氢渗透　；参考：《材料导报》2017年06期

【摘要】：利用氢渗透试验、慢应变速率拉伸试验(SSRT)研究了1 000MPa级高强钢(HSS)焊接件在海水中的氢渗透行为及其应力腐蚀敏感性,结合SEM观察了试样的断口特征,并利用电化学试验和显微组织观察分析了焊接件不同区域的氢脆特征。结果表明:相对于焊缝区(WM)和母材区(BM),热影响区(HAZ)的自腐蚀电位最负、析氢电位最正,更容易发生腐蚀和析氢行为。热影响区的氢扩散系数最大,具有较强的吸氢倾向。动态电化学充氢对高强钢焊接件的影响主要体现在对塑性的损减方面;随着极化电位的负移,高强钢焊接件的强度没有明显变化,但断面收缩率、断后延伸率均减小,断裂方式逐渐由韧性断裂变为解理断裂;当极化电位约为-930mV(vs SCE)时,高强钢焊接件的氢脆系数达25%;在不同充氢极化电位下,焊接件试样的断裂位置多在热影响区。
[Abstract]:Hydrogen permeation behavior and stress corrosion sensitivity of 1 000MPa grade high strength steel (HSS) welded parts in seawater were studied by hydrogen permeability test and slow strain rate tensile test (SSRT). The fracture characteristics of the specimens were observed with SEM. The hydrogen embrittlement characteristics in different regions of the welded parts were analyzed by electrochemical test and microstructure observation. The results showed that the characteristics of hydrogen embrittlement in different parts of the welded parts were analyzed. Compared with the weld zone (WM) and the base metal area (BM), the self corrosion potential of the heat affected zone (HAZ) is the most negative, the hydrogen evolution potential is the most positive, the corrosion and hydrogen evolution are easier to occur. The hydrogen diffusion coefficient of the heat affected zone is the largest, and the hydrogen absorption tendency is stronger. With the negative shift of the polarization potential, the strength of the welded parts of high strength steel did not change obviously, but the shrinkage rate and the elongation at the end of the fracture decreased, and the fracture mode gradually changed from ductile fracture to cleavage fracture. When the polarization potential was about -930mV (vs SCE), the hydrogen embrittlement coefficient of high strength steel welded parts reached 25%. The crack position is mostly in the heat affected zone.
【作者单位】：青岛科技大学机电工程学院;中国船舶重工集团公司第七二五研究所海洋腐蚀与防护重点实验室;
【分类号】：TG142.1;TG40

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