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采用声发射检测裂纹扩展,用照相机跟踪摄照裂纹长度,测定了37SiMnCrMoV钢经不同温度回火、亚温淬火和高温淬火等热处理后的水质应力腐蚀裂纹扩展特性。结果表明,预制裂纹试样水质应力腐蚀开裂都经历孕育期。孕育期的时间比裂纹亚临界扩展的时间大9—13倍。试样经930℃淬火、300℃回火、可获得很好的抗应力腐蚀性能。在现行的930℃淬火、270℃回火这两道工序之间增加一次870℃的两相区加热淬火,可有效地改善钢的性能:屈服强度保持160kg/mm~2,K1_c值由190kg/mm~(3/2)增至208kg/mm~(3/2),还显著地改善其抗应力腐蚀开裂的性能,增长孕育期,减慢裂纹扩展速率,亚温淬火对回火脆敏感的400℃回火试样亦有明显的效果。高温淬火试验结果表明,在1000至1200℃之间尚存在一个能获得很好性能的淬火温度。
The crack propagation was detected by acoustic emission and the camera was used to track the length of the photographic crack. The stress corrosion cracking propagation of 37SiMnCrMoV steel after heat treatment at different temperatures, sub-temperature quenching and high-temperature quenching was measured. The results show that the pre-cracked specimens undergo stress-induced corrosion cracking during the incubation period. The incubation period is 9-13 times longer than the subcritical crack propagation. The sample was quenched at 930 ℃, tempering at 300 ℃, get good resistance to stress corrosion. In the current 930 ℃ quenching, tempering at 270 ℃ between the two processes an additional 870 ℃ two-phase heating and quenching can effectively improve the performance of steel: yield strength to maintain 160kg / mm ~ 2, K1_c value from 190kg / mm ~ (3/2) to 208kg / mm ~ (3/2), but also significantly improve its resistance to stress corrosion cracking, increase the incubation period, slow down the crack propagation rate, 400 ℃ tempered samples also have significant results. The results of the high-temperature quenching test show that there is still a quenching temperature of 1000 to 1200 ° C that achieves good properties.