Microstructural evolution during partial melting and semisolid forming behaviors of two hot-rolled Cr-V-Mo tool steels

Using a multistage hot compression test machine, reheating experiments and semisolid compression tests were conducted on two commercial rolled Cr-V-Mo tool steels, SKD11 and SKD61. Austenization, grain growth, carbide dissolution, and partial melting took place during the reheating of the tool steels, and resulting in spherical semisolid slurries at certain temperatures (1300 °C for SKD11, 1405 °C for SKD61). The microstructural evolution of SKD11 and SKD61 tool steels during reheating and rapid cooling was found to be different owing to their different alloying element contents and the different distributions and morphologies of the carbides inside them. The forming characteristics of the two tool steels in the semisolid state were discussed on the basis of the results of compression tests.