A HEAT TREATMENT METHOD FOR FINING CRYSTAL PARTICLE OF BLADE MATERIAL

摘要

A heat treatment method for grain refinement of a 12Cr series high chromium martensitic blade material, which secures economic efficiency by reducing heat treatment time, and effectively refines coarse grains formed in the material, is provided. A heat treatment method for grain refinement of a 12Cr series high chromium martensitic blade material comprises the steps of: heating the 12Cr series high chromium martensitic blade material to a temperature of 940 to 970 deg.C, a high temperature not less than an Ac3 of 816 to 836 deg.C, at a heating rate of 50 deg.C/hour, and holding the material at the same temperature; holding the material at a temperature of 940 to 970 deg.C for one hour per 25 mm of the material's thickness; air cooling the structure of the material, and maintaining a cooling rate of the material to 10 to 20 deg.C/min when the material is air cooled to a temperature between 800 deg.C and 850 deg.C; and performing quality heat treatment of the material to refine grains of the material.