High rigid spheroidal graphite cast iron

Patent metadata

Field	Value
Publication number	US-9834831-B2
Application number	US-201314380846-A
Country	US
Kind code	B2
Filing date	Feb 15, 2013
Priority date	Feb 24, 2012
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

A high rigid spheroidal graphite cast iron, comprising: 2.0 mass % to less than 2.7 mass % or more than 3.0 mass % to less than 3.6 mass % of C, 1.5 to 3.0 mass % of Si, 1.0% or less of Mn, 1.0 mass % or less of Cu, 0.02 to 0.07 mass % of Mg and the residual Fe and inevitable impurities, wherein a carbon equivalent (a CE value) calculated by the mathematical expression (1): CE=C (mass %)+Si (mass %)/3 in terms of C and Si contents is 2.8 to 3.2% within a first range from 2.0 mass % to less than 2.7 mass % of C and is 3.6 to 4.2% within a second range from more than 3.0 mass % to less than 3.6 mass % of C, and the Young's modulus is 170 GPa or more.

First claim

What is claimed is:

1. A spheroidal graphite cast iron, comprising:
2.0 mass % to less than 2.7 mass % or more than 3.0 mass % to less than 3.6 mass % of C, 1.53 mass % to 2.58 mass % of Si, 1.0 mass % or less and more than 0 mass % of Mn, 1.0 mass % or less and more than 0 mass % of Cu, 0.02 mass % to 0.07 mass % of Mg and residual Fe and inevitable impurities, wherein
a carbon equivalent (a CE value) calculated by mathematical expression (1): CE=C (mass %)+Si (mass %)/3 in terms of C and Si contents is 2.8% to 3.2% within a first range from 2.0 mass % to less than 2.7 mass % of C and is 3.6% to 4.2% within a second range from more than 3.0 mass % to less than 3.6 mass % of C;
Young's modulus is 170 GPa or more;
an area ratio of concatenated structure of graphite is 50% or less; and
the mathematical expression (2): 0.09×B+A>65 is satisfied, where A is % elongation at fracture and B is a tensile strength of 529.2 to 702.7 MPa.

2. The spheroidal graphite cast iron of claim 1 , wherein the Young's modulus is 175 GPa or more.

3. The spheroidal graphite cast iron of claim 1 , wherein CE is 2.9% to 3.2% when the spheroidal graphite cast iron comprises 2.0 mass % to less than 2.7 mass % of C.

4. The spheroidal graphite cast iron of claim 3 , wherein no concatenated structure of graphite emerges.

5. The spheroidal graphite cast iron of claim 3 , wherein the Young's modulus is 180 GPa or more.

6. The spheroidal graphite cast iron of claim 1 , wherein CE is 3.8% to 4.2% when the spheroidal graphite cast iron comprises more than 3.0 mass % to less than 3.6 mass % of C.

7. The spheroidal graphite cast iron of claim 6 , wherein no concatenated structure of graphite emerges.

8. The spheroidal graphite cast iron of claim 1 , comprising 0.3 mass % or less and more than 0 mass % of Cu and 0.3 mass % or less and more than 0 mass % of Mn.

Assignees

• Kk Riken

Inventors

• Tobita Tomoyuki
• KANBAYASHI Tadaaki

Classifications

• C22C33/10

  including procedures for adding magnesium · CPC title

• C22C37/04 Primary

  containing spheroidal graphite · CPC title

• C22C33/08

  Making cast-iron alloys · CPC title

• C22C38/002

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

• C22C38/02

  containing silicon · CPC title