Fatigue Crack Growth Rate of High Stress Part of 30Cr1Mo1V Steel Turbine Rotor

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.