Chisel and steel for chisel
AssigneeKomatsu Ltd.
InventorsEiji Amada, Akihiro Ochiai, Norimasa Tsunekage, Yuko Nagaki
Life of this patent
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Abstract
A steel constituting a chisel according to the present invention includes: 0.40-0.45% by mass of carbon, 0.50-0.80% by mass of silicon, 1.00-1.30% by mass of manganese, 0.001-0.005% by mass of sulfur, 2.90-3.80% by mass of chromium, and 0.20-0.40% by mass of molybdenum, with a balance consisting of iron and an unavoidable impurity, the steel has an ideal critical diameter DI defined by Equation (1) of 600 or more: DI=7·(% C)1/2·(1+0.64·% Si)·(1+4.1·% Mn)·(1+2.83·% P)·(1−0.62·% S)·(1+2.33·% Cr)·(1+3.14·% Mo) (1).
Claims15
A steel body constituting by a steel consisting of:
- 0.40% by mass or more and 0.45% by mass or less of carbon (C);
- 0.50% by mass or more and 0.80% by mass or less of silicon (Si);
- 1.00% by mass or more and 1.30% by mass or less of manganese (Mn);
- 0.001% by mass or more and 0.005% by mass or less of sulfur (S);
- 2.90% by mass or more and 3.80% by mass or less of chromium (Cr);
- 0.20% by mass or more and 0.40% by mass or less of molybdenum (Mo);
- and
- a balance consisting of iron and one or more unavoidable impurities with 0.020% by mass or less of phosphorous (P),
- wherein the steel has an ideal critical diameter DI defined by Equation (1) of 600 or more:
- DI
- =
- 7
- ·
- (
- %
-
-
- C
- )
- 1
- 2
- ·
- (
- 1
- +
- 0.64
- ·
- %
-
- Si
- )
- ·
- (
- 1
- +
- 4.1
- ·
- %
-
- Mn
- )
- ·
- (
- 1
- +
- 2.83
- ·
- %
-
- P
- )
- ·
- (
- 1
- -
- 0.62
- ·
- %
-
- S
- )
- ·
- (
- 1
- +
- 2.33
- ·
- %
-
- Cr
- )
- ·
- (
- 1
- +
- 3.14
- ·
- %
-
- Mo
- )
- wherein % is by mass, and
- wherein the steel body is a rod having a diameter of at least 150 mm, and
- a hardness (HRC) of an entire cross section of the steel body is within the range of from 49 to 54 HRC.
A chisel constituted by a steel consisting of:
- 0.40% by mass or more and 0.45% by mass or less of carbon (C);
- 0.50% by mass or more and 0.80% by mass or less of silicon (Si);
- 1.00% by mass or more and 1.30% by mass or less of manganese (Mn);
- 0.001% by mass or more and 0.005% by mass or less of sulfur (S);
- 2.90% by mass or more and 3.80% by mass or less of chromium (Cr);
- 0.20% by mass or more and 0.40% by mass or less of molybdenum (Mo);
- and
- a balance consisting of iron and one or more unavoidable impurities with 0.020% by mass or less of phosphorous (P),
- wherein the steel has an ideal critical diameter DI defined by Equation (1) of 600 or more:
- DI
- =
- 7
- ·
- (
- %
-
-
- C
- )
- 1
- 2
- ·
- (
- 1
- +
- 0.64
- ·
- %
-
- Si
- )
- ·
- (
- 1
- +
- 4.1
- ·
- %
-
- Mn
- )
- ·
- (
- 1
- +
- 2.83
- ·
- %
-
- P
- )
- ·
- (
- 1
- -
- 0.62
- ·
- %
-
- S
- )
- ·
- (
- 1
- +
- 2.33
- ·
- %
-
- Cr
- )
- ·
- (
- 1
- +
- 3.14
- ·
- %
-
- Mo
- )
- wherein % is by mass, and
- wherein the chisel has a diameter of at least 150 mm, and
- a hardness (HRC) of an entire cross section of the chisel vertical to an axial direction of the chisel is within the range of from 49 to 54 HRC.
Dependencies are inferred from the claim text.