采用高压釜研究了国产52合金异种金属焊接材料在模拟压水堆核电站一回路高温水环境中的应力腐蚀裂纹扩展行为，并通过直流电位降（DCPD）技术实时监测了裂纹扩展长度。结果表明：国产52合金异种金属焊接材料在模拟压水堆一回路高温水环境中出现轻微的应力腐蚀开裂，裂纹扩展速率为1.93×10^-9 mm/s，直流电位降裂纹扩展监测结果与实测结果符合性较好，裂纹扩展过程以局部穿晶扩展为主，裂纹扩展速率比82/182异种金属焊接材料低2个数量级，这与国外研究机构试验结果一致。

Autoclave was used to study the stress corrosion cracking (SCC) behaviors of domestic alloy 52 dissimilar welding materials in simulated PWR nuclear power plant primary water environment,and the length of crack expending was on-line monitored by direct current potential drop (DCPD). The results showed that very slight SCC happened when domestic 52 alloy dissimilar welding under loading in the environment of simulated PWR primary water, and the crack growth rate was 1.93×10^-9 mm/s. The monitoring results from DCPD were in good agreement with the measured results. TGSCC was the main cracking path. The crack growth rates were lower than those of 82/182 alloy dissimilar metal welding materials in two orders of magnitude and consistent with the experimental results got by foreign research inistitutions.