利用小冲杆试验对304L不锈钢进行了应力腐蚀敏感性评估, 研究了加载速度和腐蚀介质对评估结果的影响, 并对小冲杆试样的断口形貌和显微组织进行了分析。结果表明: 最适合304L不锈钢评估的小冲杆应力腐蚀试验介质为1.0 mol·L-1 NaCl+0.5 mol·L-1 HCl混合溶液, 加载速度为3×10-3 mm·min-1; 在以上介质中, 304L不锈钢小冲杆试样断口以穿晶解理断裂为主, 部分为准解理断裂; 小冲杆试验法是一种有效的应力腐蚀敏感性评估手段, 且具有快速近乎无损等特点。

Small punch test (SPT) was used to evaluate stress corrosion cracking (SCC) susceptibility of 304L stainless steel, effects of load rate and corrosion medium on evaluating results were studied, and fracture appearance and microstructure evolution of the small punch sample were analysed. The results show that the most appropriate corrosion medium for evaluating stress corrosion cracking susceptibility of 304L stainless steel was mix solution of 1.0 mol·L-1 NaCl and 0.5 mol·L-1 HCl , and the most appropriatin load rate was 3×10-3 mm·min-1, the main fracture of 304L stainless steel sample punch sample was main cleavage frature, and part of quasi-cleavage appearance was observed. The results proved that small punch test was an effective stress corrosion cracking susceptibility evaluation method, and which was fast and nondestructive.