30Cr1Mo1V钢汽轮机转子高应力段的疲劳裂纹扩展速率
Fatigue Crack Growth Rate of High Stress Part of 30Cr1Mo1V Steel Turbine Rotor
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摘要: 在某已服役了16 a的30Cr1Mo1V钢汽轮机转子的高应力段取样制作成紧凑拉伸试样, 用MTS 810.50试验机进行室温和538 ℃下的疲劳裂纹扩展速率试验。结果表明: 该钢疲劳裂纹稳定扩展阶段的疲劳裂纹扩展速率适用于Paris公式, 室温下的疲劳裂纹扩展速率方程为da/dN=2.2101×10-8(ΔK)2.9163, 538 ℃下的疲劳裂纹扩展速率方程为da/dN=9.8794×10-8(ΔK)2.6844; 对于30Cr1Mo1V转子钢, 温度升高, 疲劳裂纹扩展速率加快; 30Cr1Mo1V转子钢在疲劳裂纹稳定扩展阶段存在转折点, 将该阶段又细分为两段, 经过转折点后疲劳裂纹扩展速率的增速减慢; 与原始材料相比, 已服役16 a的30Cr1Mo1V钢汽轮机转子高应力段材料的疲劳裂纹扩展速率增大。Abstract: The fatigue cracks growth rate test of compact tensile specimens sampling from high stress part of 30Cr1Mo1V steel turbine rotor which had served for 16 years was conducted with MTS 810.50 fatigue system at room temperature and 538 ℃. The results show that the fatigue cracks growth rate da/dN of stable extension stage of fatigue cracks applied to Pairs formula, and fatigue crack growth rate equation of the rotor steel was da/dN = 2.2101×10-8(ΔK)2.9163 at room temperature and da/dN = 9.8794×10-8 (ΔK)2.6844 at 538 ℃. With the increase of temperature, the fatigue cracks growth rate became quicker. A turning point existed at the stable extension stage which divided the da/dN-ΔK curves into two parts, and the fatigue cracks growth rate decreased when passed the point. Compared to the original material, the fatigue cracks growth rate of the served 30Cr1Mo1V rotor steel increased.