Tool steel having strength and high impact toughness

Patent metadata

Field	Value
Publication number	US-11008634-B2
Application number	US-201816174780-A
Country	US
Kind code	B2
Filing date	Oct 30, 2018
Priority date	Oct 2, 2018
Publication date	May 18, 2021
Grant date	May 18, 2021

Abstract

A tool steel having strength and high impact toughness incudes 0.7 to 0.9 wt % of C, 0.4 to 0.6 wt % of Si, 0.4 to 0.6 wt % of Mn, 7.0 to 9.0 wt % of Cr, 1.5 to 2.5 wt % of Mo, up to 1.0 wt % or less (excluding 0 wt %) of V, 0.01 to 0.06 wt % of Ce, and a remainder of Fe and inevitable impurities, wherein the tool steel has a hardness of 59 to 65 HRC and an impact toughness of 30 to 42 J/cm2. The tool steel has super-high-strength combined with high impact toughness due to inclusion of Ce, thus reducing primary carbide content in an as-cast state and after solution treatment and tempering.

First claim

What is claimed is:

1. A tool steel having strength and impact toughness, consisting of:
0.7 to 0.9 wt % of C;
0.4 to 0.6 wt % of Si;
0.4 to 0.6 wt % of Mn;
7.0 to 9.0 wt % of Cr;
1.5 to 2.5 wt % of Mo;
up to 1.0 wt % or less (excluding 0 wt %) of V;
0.01 to 0.06 wt % of Ce; and
a remainder of Fe and inevitable impurities,
wherein the tool steel has a hardness of 59 to 65 HRC and an impact toughness of 30 to 42 J/cm 2 .

Assignees

• Korea Inst Ind Tech

Inventors

• Lee Min-Ha
• Jun Joong-Hwan
• Lim Chae-Ho
• Kim Song-Yi
• Han Jin-Gu

Classifications

• C21D8/00

  Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment (hardening articles or materials formed by forging or rolling with no further heating beyond that required for the formation C21D1/02) · CPC title

• C21D6/002

  containing Cr (C21D6/004 takes precedence) · CPC title

• C22C38/22 Primary

  with molybdenum or tungsten · CPC title

• C21D1/32

  Soft annealing, e.g. spheroidising · CPC title

• C22C38/005

  containing rare earths, i.e. Sc, Y, Lanthanides · CPC title