HOT TOOL STEEL EXCELLENT IN HARDENING PROPERTY AND TOUGHNESS

• Main Author: MAEDA MASAHITO
• Format: Patent
• Language: English; Japanese
• Published: 07.02.2019
• Subjects: ALLOYS; CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; METALLURGY; TREATMENT OF ALLOYS OR NON-FERROUS METALS

To provide a hot tool steel used for forging mold of a large size product, in which hardening is easy to enter into a center part of the mold, high in toughness and small in anisotropy of the toughness.SOLUTION: There is provided a hot tool steel excellent in hardening property and toughness, consisting of a steel containing, by mass%, C:0.37 to 0.45%, Si:0.3 to 1.2%, Mn:0.6 to 1.5%, Ni:0.3 to 1.0%, Cr:1.0 to 2.0%, Mo:1.1 to 1.4%, V:0.1 to 0.3% and the balance Fe with inevitable impurities, and further having a value of a formula L, which is a formula of alloy components L=-0.4×Si-9.7×Mn+3.7×Ni+54.4×Mo, of 54 to 65, and a value of a formula Y, which is a formula of the alloy components Y=-17.1×C+0.1×Si+0.2×Mn+0.2×Ni+0.5×Cr+Mo+5.0, of 0.0 or more.SELECTED DRAWING: None 【課題】 大型製品の鍛造用金型に使用され、金型の中心部まで焼きが入り易く、靭性が高く、かつ靭性の異方性の小さい熱間工具鋼を得る。【解決手段】 質量％で、Ｃ：０．３７〜０．４５％、Ｓｉ：０．３〜１．２％、Ｍｎ：０．６〜１．５％、Ｎｉ：０．３〜１．０％、Ｃｒ：１．０〜２．０％、Ｍｏ：１．１〜１．４％、Ｖ：０．１〜０．３％を含有し、残部Ｆｅおよび不可避不純物からなる鋼からなり、さらに、合金成分の式Ｌ＝−０．４×Ｓｉ−９．７×Ｍｎ＋３．７×Ｎｉ＋５４．４×Ｍｏとするとき、式Ｌの値は５４〜６５であり、かつ、合金成分の式Ｙ＝−１７．１×Ｃ＋０．１×Ｓｉ＋０．２×Ｍｎ＋０．２×Ｎｉ＋０．５×Ｃｒ＋Ｍｏ＋５．０とするとき、式Ｙの値は０．０以上であること、を特徴とする、焼入れ性および靱性に優れた熱間工具鋼である。【選択図】 なし