Erosion Resistance And Its Mechanism For Flame-Hardened 12cr Steel By High Speed Water Drop Impacts

In this study, the water drop impact erosion properties of 12Cr steel surface-hardened by the flame hardening process have been studied. For this, both the maximum erosion depth d(e,max). and volume loss V-e-with the number of cumulative impacts n have been investigated for the flame-hardened 12Cr steels with different hardnesses. Typically all the samples showed an erosion-time characteristic involving an incubation period initially followed by a steady state period. Compared to those for the as-received 12Cr steel, the flame-hardened ones showed an excellent erosion resistance to water drop impacts, showing a 2.2 similar to 2.8 times higher incubation time t(i) and 5-8 times lower erosion rate a. In the incubation period the as-received 12Cr steel was deformed by a ductile depression and ploughing, while the flame-hardened one by fatigue cracks and a brittle platelet deformation. In the steady state period the damage was progressed by a cleavage fracture for both the stages.