Ferritic free-cutting stainless steel
AssigneeDaido Steel Co., Ltd.
InventorsNaoki SEI, Chihiro FURUSHO, Yoshihiko KOYANAGI
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Abstract
The present invention relates to a ferritic free-cutting stainless steel consisting of: C≤0.02 mass %, Si≤0.50 mass %, 0.20≤Mn≤1.00 mass %, P≤0.05 mass %, 0.20≤S≤0.70 mass %, Cu≤1.5 mass %, Ni≤1.5 mass %, 10.0≤Cr≤20.0 mass %, Mo≤2.0 mass %, 0.30≤Al≤1.00 mass % O≤0.010 mass %, N≤0.030 mass %, and optionally at least one selected from the group consisting of: B≤0.0100 mass %, Mg≤0.0100 mass %, and Ca≤0.0100 mass %, with a balance being Fe and unavoidable impurities, in which the following three expressions are satisfied: ([Cr]+[Mo]+1.5[Si]+4[Al])/([Ni]+0.5[Mn]+30[C]+30[N])≥7, 900([C]+[N])+170[Si]+450[P]+12[Cr]+30[Mo]+10[Al]≤300, and 0.285≤[Mn]/[S]≤1.5, where [X] represents a content (mass %) of an element X.
Claims6
A ferritic free-cutting stainless steel consisting of:
- C≤0.02 mass %,
- Si≤0.50 mass %,
- 0.20≤Mn≤1.00 mass %,
- P≤0.05 mass %,
- 0.20≤S≤0.70 mass %,
- Cu≤1.5 mass %,
- Ni≤1.5 mass %,
- 10.0≤Cr≤20.0 mass %,
- Mo≤2.0 mass %,
- 0.30≤Al≤1.00 mass %
- O≤0.010 mass %,
- N≤0.030 mass %, and
- optionally at least one selected from the group consisting of:
- B≤0.0100 mass %,
- Mg≤0.0100 mass %, and
- Ca≤0.0100 mass %,
- with a balance being Fe and unavoidable impurities, wherein
- the following expression (1) to expression (3) are satisfied:
- (
- [
- Cr
- ]
- +
- [
- Mo
- ]
- +
- 1.5
- [
- Si
- ]
- +
- 4
- [
- Al
- ]
- )
- /
- (
- [
- Ni
- ]
- +
- 0.5
- [
- Mn
- ]
- +
- 30
- [
- C
- ]
- +
- 30
- [
- N
- ]
- )
- ≥
- 7
- (
- 1
- )
- 900
-
- (
- [
- C
- ]
- +
- [
- N
- ]
- )
- +
- 170
- [
- Si
- ]
- +
- 450
- [
- P
- ]
- +
- 12
- [
- Cr
- ]
- +
- 30
- [
- Mo
- ]
- +
- 10
- [
- Al
- ]
- ≤
- 300
- (
- 2
- )
- 0.285
- ≤
- [
- Mn
- ]
-
- /
- [
- S
- ]
- ≤
- 1.5
- (
- 3
- )
- where [X] represents a content (mass %) of an element X.
Dependencies are inferred from the claim text.