Austenitic heat-resisting cast steel

Patent metadata

Field	Value
Publication number	US-10633729-B2
Application number	US-201615575423-A
Country	US
Kind code	B2
Filing date	Jun 2, 2016
Priority date	Jun 4, 2015
Publication date	Apr 28, 2020
Grant date	Apr 28, 2020

Abstract

Provided is austenitic heat-resisting cast steel that is excellent in both of the heat resistance and the machinability. Austenitic heat-resisting cast steel, includes: C: 0.1 to 0.4 mass %; Si: 0.8 to 2.5 mass %; Mn: 0.8 to 2.0 mass %; S: 0.05 to 0.30 mass %; Ni: 5 to 20 mass %; N: 0.3 mass % or less; Zr: 0.01 to 0.20 mass %; Ce: 0.01 to 0.10 mass %; one type or more of the elements selected from the following groups of (i) to (iii), at least including (i), (i) Cr: 14 to 24 mass %, (ii) Nb: 1.5 mass % or less, and (iii) Mo: 3.0 mass % or less; and Fe and inevitable impurity as a remainder.

First claim

The invention claimed is:

1. Austenitic heat-resisting cast steel, comprising:
C: 0.1 to 0.4 mass %;
Si: 0.8 to 2.5 mass %;
Mn: 0.8 to 2.0 mass %;
S: 0.05 to 0.30 mass %;
Ni: 5 to 20 mass %;
N: 0.3 mass % or less;
Zr: 0.01 to 0.20 mass %;
Ce: 0.01 to 0.10 mass %;
Cr: 14 to 24 mass %;
one or both of the elements of the following groups (i) or (ii);
(i) Nb: 1.5 mass % or less; or
(ii) Mo: 3.0 mass % or less; and

Fe and inevitable impurity as a remainder.

2. The austenitic heat-resisting cast steel according to claim 1 , wherein the steel includes the element of group (i).

3. The austenitic heat-resisting cast steel according to claim 1 , wherein the steel includes the element of group (ii).

4. The austenitic heat-resisting cast steel according to claim 1 , wherein the steel includes the element of group (i) and the element of group (ii).

5. The austenitic heat-resisting cast steel according to claim 1 , wherein a value of the parameter Pm in the following expression (1) based on the mass percent of elements in the steel is less than or equal 0.09;
Pm=(0.0038Ni+0.119C+0.0014Cr+0.0136Mo+0.0344Nb)−(0.3129S+0.0353Zr+0.2966Ce)−0.04225.  Expression (1):

6. The austenitic heat-resisting cast steel according to claim 1 , wherein a value of the parameter in Pa in the following expression (2) based on the mass percent of elements in the steel is less than or equal to 310,
Pσ=399.25+129.78C−1.75Ni−6.23Cr−9.88Mo−26.88Nb.  Expression (2):

7. The austenitic heat-resisting cast steel according to claim 5 , wherein a value of the parameter in Pa in the following expression (2) based on the mass percent of elements in the steel is less than or equal to 310,
Pσ=399.25+129.78C−1.75Ni−6.23Cr−9.88Mo−26.88Nb.  Expression (2):

8. The austenitic heat-resisting cast steel according to claim 1 , wherein a content of C is greater than a content of S.

9. The austenitic heat-resisting cast steel according to claim 1 , wherein C is 0.3 to 0.4 mass %.

Assignees

• Toyota Motor Co Ltd
• Toyota Chuo Kenkyusho Kk

Inventors

• Ueda Takamichi
• Ueno Harumi
• Hijii Takumi
• HIRAI Hitomi
• Maeshima Takashi
• Nishino Kazuaki
• Ito Hirofumi

Classifications

• C22C38/48

  with niobium or tantalum · CPC title

• C22C38/005 Primary

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

• C22C38/02

  containing silicon · CPC title

• C22C38/002

  containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60 · CPC title

• C22C38/50 Primary

  with titanium or zirconium · CPC title