STEEL FOR MOLD AND MOLD

• Main Authors: UMEMORI NAOKI, HIGUCHI SHIGEKI
• Format: Patent
• Language: English; Japanese
• Published: 17.06.2021
• Subjects: ADDITIVE MANUFACTURING TECHNOLOGY; ADDITIVE MANUFACTURING, i.e. MANUFACTURING OFTHREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVEAGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING,STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING; ALLOYS; CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; METALLURGY; PERFORMING OPERATIONS; TRANSPORTING; TREATMENT OF ALLOYS OR NON-FERROUS METALS

To provide steel for mold having high softening resistance, and a mold using the same.SOLUTION: Steel for mold contains 0.28 to 0.65 mass% C, 0.01 to 0.30 mass% Si, 1.5 to 3.0 mass% Mn, 0.5 to 1.4 mass% Cr, 1.9 to 4.0 mass% Mo+W/2, 0.2 to 1.0 mass% V, and 0.01 to 0.10 mass% N, and the balance Fe with inevitable impurities. The mold is composed of steel for mold having the composition, an amount of (Mo, W) carbide with a diameter of 0.2 μm or less is 1.2 mass% or more, a ratio (mass ratio) of the amount of (Mo, W) carbide to an amount to Cr carbide is 11 or more, and change in hardness is 15 HRC or less. The mold preferably has initial hardness of 52 HRC or harder and/or thermal conductivity at room temperature of 30 W/(m K) or more.SELECTED DRAWING: Figure 1 【課題】軟化抵抗が高い金型用鋼、及びこれをを用いた金型を提供すること。【解決手段】金型用鋼は、０．２８≦Ｃ≦０．６５ｍａｓｓ％、０．０１≦Ｓｉ≦０．３０ｍａｓｓ％、１．５≦Ｍｎ≦３．０ｍａｓｓ％、０．５≦Ｃｒ≦１．４ｍａｓｓ％、１．９≦Ｍｏ＋Ｗ／２≦４．０ｍａｓｓ％、０．２≦Ｖ≦１．０ｍａｓｓ％、及び、０．０１≦Ｎ≦０．１０ｍａｓｓ％を含み、残部がＦｅ及び不可避的不純物からなる。金型は、上記組成を有する金型用鋼からなり、直径が０．２μｍ以下である(Ｍｏ,Ｗ)炭化物量が１．２ｍａｓｓ％以上であり、前記(Ｍｏ,Ｗ)炭化物量／Ｃｒ炭化物量比（質量比）が１１以上であり、硬さ変化が１５ＨＲＣ以下である。金型は、初期硬さが５２ＨＲＣ以上であるもの、及び／又は、室温における熱伝導率が３０Ｗ／(ｍ・Ｋ)以上であるものが好ましい。【選択図】図１