Abstract: A hot work tool steel or hot work tool contains, in mass %, 0.25 to 0.45% of C, 0.1 to 0.4% of Si, 0.5 to 0.9% of Mn, 0.2 to 0.6% of Ni, 4.9 to 5.5% of Cr, 1.9 to 2.3% of Mo or 1/2W by itself or 1.9 to 2.3% of (Mo+1/2W) in combination, 0.6 to 0.9% of V, and a balance of Fe and impurities, and value A and value B calculated by the following Formula 1 and Formula 2 satisfy that value A is 6.00 or more and value B is 1.00 or less. Value A=?0.7(% Si)+1.5(% Mn)+1.3(% Ni)+0.9(% Cr)+0.6(%(Mo+1/2W))+0.3(% V)??Formula 1: Value B=1.9(% C)+0.043(% Si)+0.12(% Mn)+0.09(% Ni)+0.042(% Cr)+0.03(%(Mo+1/2W))?0.

Abstract: Provided are a laminate shaped article made of a maraging steel and having excellent toughness, a method for manufacturing the same, and a metal powder for laminate shaping. The laminate shaped article is made of a maraging steel comprising 0.1-5.0 mass % of Ti. When sis is performed on concentration distribution of Ti in a cross section parallel to a lamination direction of the above laminate shaped article, a length of a linear Ti-rich portion having a Ti concentration B of (1.5×A) or more with respect to an average Ti concentration A in the cross section is 15 ?m or less. In addition, the method for manufacturing the laminate shaped article uses a metal powder made of a maraging steel comprising 0.1-5.0 mass % of Ti, and a heat source output is set to 50-330 W and a scanning speed is set to 480-3000 mm/sec during the laminate shaping.

Abstract: Provided are a steel that is for a die and that enables production of a die being for hot working and having both high hardness and high thermal conductivity; a die for hot working; and a manufacturing method for the same. The steel for a hot working die has a compositional makeup containing, in mass %, 0.45-0.65% of C, 0.1-0.6% of Si, 0.1-2.5% of Mn, 1.0-6.0% of Cr, 1.2-3.5% of (Mo+½W) where Mo and W are contained independently or in combination, 0.1-0.5% of V, 0.15-0.6% of Ni, 0.1-0.6% of Cu, and 0.1-0.6% of Al, the balance being Fe and inevitable impurities. Further, this die for hot working has said compositional makeup, and this manufacturing method is for manufacturing said die for hot working.

Abstract: A die steel which enables manufacturing a hot stamp die that has both high hardness and high thermal conductivity, a hot stamp die, and a manufacturing method thereof are provided. This steel for a hot stamp die has a component composition, in mass% of 0.45-0.65% C, 0.1-0.6% Si, 0.1-0.3% Mn, 2.5-6.0% Cr, 1.2-2.6% Mo, and 0.4-0.8% V, the remainder being Fe and unavoidable impurities. Further, this hot stamp die has the aforementioned component composition, and the manufacturing method is for manufacturing said hot stamp die.

Abstract: The hot work tool steel or hot work tool contains, in mass %, 0.25 to 0.45% of C, 0.1 to 0.4% of Si, 0.5 to 0.9% of Mn, 0 to 0.6% of Ni, 4.9 to 5.5% of Cr, 1.3 to 2.3% of Mo or 1/2W by itself or 1.3 to 2.3% of (Mo+1/2W) in combination, 0.6 to 0.9% of V, and a balance of Fe and impurities, and value A and value B calculated by the following Formula 1 and Formula 2 satisfy that value A is 6.00 or more and value B is 1.00 or less. Value A=?0.7(% Si)+1.5(% Mn)+1.3(% Ni)+0.9(% Cr)+0.6(%(Mo+1/2W))+0.3(% V) ??Formula 1 Value B=1.9(% C)+0.043(% Si)+0.12(% Mn)+0.09(% Ni)+0.042(% Cr)+0.03(%(Mo+1/2W))?0.

Abstract: An outer layer of a rolling roll having a chemical composition comprising by mass 1.3-2.8% of C, 0.3-1.8% of Si, 0.3-2.5% of Mn, 0-6.5% of Ni, 1-10% of Cr, 0.9-6% of Mo, 0-8% of W, 0.5-6% of V, 0-3% of Nb, and 0% or more and less than 0.01% of B, the balance being Fe and inevitable impurities, and meeting the formulae (1): 1000?1177?52C+14Si?11Mn+6.8Cr+1W+0.65Mo+12V+15Nb?1115, and (2): 5?Cr+Mo+0.5W+V+1.2Nb?15, wherein C, Si, Mn, Cr, W, Mo, V and Nb represent % by mass of these elements, and a structure containing eutectic carbide without graphite.

Abstract: An additive layer manufactured hot work tool according to the present disclosure includes a component composition of by mass %, C: 0.3-0.5% to Si: 2.0% or less, Mn: 1.5% or less, P: 0.05% or less, S: 0.05% or less, Cr: 3.0 to 6.0%, 1 or 2 kinds of compounds of Mo and W, a relation between Mo and W being represented by a relational expression of (Mo+1/2W): 0.5 to 3.5%, V: 0.1 to 1.5%, Ni: 0 to 1.0%, Co: 0 to 1.0%, and Nb: 0 to 0.3%, and with Fe and an unavoidable impurity as a remainder, and an area ratio of defects having an area of 1 ?m2 or more is 0.6% or less in a cross section parallel to the amination direction.

Abstract: Provided are a laminate shaped article made of a maraging steel and having excellent toughness, a method for manufacturing the same, and a metal powder for laminate shaping. The laminate shaped article is made of a maraging steel comprising 0.1-5.0 mass % of Ti. When sis is performed on concentration distribution of Ti in a cross section parallel to a lamination direction of the above laminate shaped article, a length of a linear Ti-rich portion having a Ti concentration B of (1.5×A) or more with respect to an average Ti concentration A in the cross section is 15 ?m or less. In addition, the method for manufacturing the laminate shaped article uses a metal powder made of a maraging steel comprising 0.1-5.0 mass % of Ti, and a heat source output is set to 50-330 W and a scanning speed is set to 480-3000 mm/sec during the laminate shaping.

Abstract: Provided are a high-speed tool steel having excellent hot workability, and excellent damage resistance when made into various tools; a material for tools, and a method for producing the same. The high-speed tool steel contains, in mass %, 0.9-1.2% of C, 0.1-1.0% of Si, 1.0% or less of Mn, 3.0-5.0% of Cr, 2.1-3.5% of W, 9.0-10.0% of Mo, 0.9-1.2% of V, 5.0-10.0% of Co, 0.020% or less of N, and the remainder being Fe and impurities, wherein an M value calculated by a formula satisfies ?1.5?M value?1.5. Formula: M value=?9.500+9.334[% C]?0.275[% Si]?0.566[% W]?0.404[% Mo]+3.980[% V]+0.166[% Co], where the characters in brackets [ ] indicate the contained amounts (mass %) of the respective elements. The present invention also pertains to: a material for tools, which is obtained by using the high-speed tool steel; and a method for producing the material for tools.

Abstract: An outer layer of a rolling roll having a chemical composition comprising by mass 1.3-2.8% of C, 0.3-1.8% of Si, 0.3-2.5% of Mn, 0-6.5% of Ni, 1-10% of Cr, 0.9-6% of Mo, 0-8% of W, 0.5-6% of V, 0-3% of Nb, and 0% or more and less than 0.01% of B, the balance being Fe and inevitable impurities, and meeting the formulae (1): 1000?1177?52C+14Si?11Mn+6.8Cr+1W+0.65Mo+12V+15Nb?1115, and (2): 5?Cr+Mo+0.5W+V+1.2Nb?15, wherein C, Si, Mn, Cr, W, Mo, V and Nb represent % by mass of these elements, and a structure containing eutectic carbide without graphite.

Abstract: Provided are: a method for producing a high-speed tool steel material capable of increasing carbides in the structure of a high-speed tool steel product; a method for producing a high-speed tool steel product; and a high-speed tool steel product. The method for producing a high-speed tool steel material is provided with: a casting step for casting molten steel to obtain a steel ingot; a blooming step for heating the steel ingot obtained in said casting step to a temperature higher than 1120° C. and thereafter hot-working same to obtain an intermediate material; and a finishing step for heating the intermediate material obtained in the blooming step to a temperature of 900-1120° C. and thereafter hot-working same to obtain the high-speed tool steel material. Further, said method for producing a high-speed tool steel material is provided with an annealing step for annealing the high-speed tool steel material obtained in said finishing step.

Abstract: Provided are: a method for producing a high-speed tool steel material capable of increasing carbides in the structure of a high-speed tool steel product; a method for producing a high-speed tool steel product; and a high-speed tool steel product. The method for producing a high-speed tool steel material is provided with: a casting step for casting molten steel to obtain a steel ingot; a blooming step for heating the steel ingot obtained in said casting step to a temperature higher than 1120° C. and thereafter hot-working same to obtain an intermediate material; and a finishing step for heating the intermediate material obtained in the blooming step to a temperature of 900-1120° C. and thereafter hot-working same to obtain the high-speed tool steel material. Further, said method for producing a high-speed tool steel material is provided with an annealing step for annealing the high-speed tool steel material obtained in said finishing step.

Abstract: Provided are a high-speed tool steel having excellent hot workability, and excellent damage resistance when made into various tools; a material for tools, and a method for producing the same. The high-speed tool steel contains, in mass %, 0.9-1.2% of C, 0.1-1.0% of Si, 1.0% or less of Mn, 3.0-5.0% of Cr, 2.1-3.5% of W, 9.0-10.0% of Mo, 0.9-1.2% of V, 5.0-10.0% of Co, 0.020% or less of N, and the remainder being Fe and impurities, wherein an M value calculated by a formula satisfies ?1.5?M value?1.5. Formula: M value=?9.500+9.334[% C]?0.275[% Si]?0.566[% W]?0.404[% Mo]+3.980[% V]+0.166[% Co], where the characters in brackets [ ] indicate the contained amounts (mass %) of the respective elements. The present invention also pertains to: a material for tools, which is obtained by using the high-speed tool steel; and a method for producing the material for tools.

Abstract: Provided are: a method for producing a high-speed tool steel material capable of increasing carbides in the structure of a high-speed tool steel product; a method for producing a high-speed tool steel product; and a high-speed tool steel product. The method for producing a high-speed tool steel material is provided with: a casting step for casting molten steel to obtain a steel ingot; a blooming step for heating the steel ingot obtained in said casting step to a temperature higher than 1120° C. and thereafter hot-working same to obtain an intermediate material; and a finishing step for heating the intermediate material obtained in the blooming step to a temperature of 900-1120° C. and thereafter hot-working same to obtain the high-speed tool steel material. Further, said method for producing a high-speed tool steel material is provided with an annealing step for annealing the high-speed tool steel material obtained in said finishing step.

Abstract: A high speed tool steel containing, by mass percent, 0.5-1.5% of C; 1.0% or less of Si; 1.0% or less of Mn; 3.0-5.0% of Cr; 15.0-25.0% of one or two kinds of W and Mo according to a formula (W+2Mo); 1.0-less than 1.5% of V; 5.0-10.0% of Co; and a remainder including Fe and impurities, the high speed tool steel further containing 0.0005-0.004% of Ca and 0.005-0.015% of N. Also, a material for a blade edge that is made of the high speed tool steel and a cutting tool made by welding the material for the blade edge to a body material. Further, a manufacturing method of the material for the blade edge.

Abstract: A high speed tool steel containing, by mass percent, 0.5-1.5% of C; 1.0% or less of Si; 1.0% or less of Mn; 3.0-5.0% of Cr; 15.0-25.0% of one or two kinds of W and Mo according to a formula (W+2Mo); 1.0-less than 1.5% of V; 5.0-10.0% of Co; and a remainder including Fe and impurities, the high speed tool steel further containing 0.0005-0.004% of Ca and 0.005-0.015% of N. Also, a material for a blade edge that is made of the high speed tool steel and a cutting tool made by welding the material for the blade edge to a body material. Further, a manufacturing method of the material for the blade edge.

Abstract: A high speed tool steel, which is high in impact value and free from variations in tool performance, comprising, by mass %, of: 0.4?C?0.9; Si?1.0; Mn?1.0; 4?Cr?6; 1.6-6 in total of either or both of W and Mo in the form of (½W+Mo) wherein W?3; 0.5-3 in total of either or both of V and Nb in the form of (V+Nb); wherein carbides dispersed in the matrix of the tool steel have an average grain size of ?0.5 ?m and a dispersion density of particles of the carbides is of ?80×103 particles/mm2.

Abstract: A high speed tool steel, which is high in impact value and free from variations in tool performance, comprising, by mass %, of: 0.4?C?0.9; Si?1.0; Mn?1.0; 4?Cr?6; 1.6-6 in total of either or both of W and Mo in the form of (½W+Mo) wherein W?3; 0.5-3 in total of either or both of V and Nb in the form of (V+Nb); wherein carbides dispersed in the matrix of the tool steel have an average grain size of ?0.5 ?m and a dispersion density of particles of the carbides is of?80×103 particles/mm2.

Abstract: A high speed tool steel, which is high in impact value and free from variations in tool performance, comprising, by mass %, of: 0.4?C?0.9; Si?1.0; Mn?1.0; 4?Cr?6; 1.5–6 in total of either or both of W and Mo in the form of (½W+Mo) wherein W?3; 0.5–3 in total of either or both of V and Nb in the form of (V+Nb); wherein carbides dispersed in the matrix of the tool steel have an average grain size of ?0.5 ?m and a dispersion density of particles of the carbides is of ?80×103 particles/mm2.

Abstract: A high speed tool steel, which is high in impact value and free from variations in tool performance, comprising, by mass %, of: 0.4≦C≧0.9; S1≦1.0; Mn≦1.0; 4≦Cr≧6; 1.5-6 in total of either or both of W and Mo in the form of (1/2 W+Mo) wherein W≦3; 0.5-3 in total of either or both of V and Nb in the form of (V+Nb); wherein carbides dispersed in the matrix of the tool steel have an average grain size of ≦0.5 &mgr;m and a dispersion density of particles of the carbides is of ≧80×103 particles/mm2.