HOT WORK TOOL MATERIAL AND METHOD FOR MANUFACTURING HOT WORK TOOL

摘要

Provided are a hot work tool material having an annealed structure effective for producing a finer quenched and tempered structure when made into a hot work tool, and a method for manufacturing a hot work tool. A hot work tool material which has an annealed structure and which is used upon being quenched and tempered, wherein the hot work tool material has a composition that can be adjusted to a martensite structure by the aforementioned quenching, and ferrite grains in a cross-section of the annealed structure of the hot work tool material have, in an oversize cumulative distribution based on the cross-sectional area of the ferrite grains, a grain diameter distribution such that the grain diameter is 25 μm or less as a circle equivalent diameter when the cumulative cross-sectional area is 90% of the total cross-sectional area. In addition, a method for manufacturing a hot work tool in which quenching and tempering is performed on the aforementioned hot work tool material.

主权项

1. A hot work tool material used after quenched and tempered, having an annealed structure and a composition such that the material has a martensitic structure after quenched,
wherein the annealed structure comprises ferrite grains in a cross-sectional structure, the ferrite grains having, in an oversize cumulative distribution based on a cross-sectional area of the ferrite grains, a grain diameter distribution such that the grain diameter is not greater than 25 μm as a circle equivalent diameter when the cumulative cross-sectional area is 90% of the total cross-sectional area.