Gray cast iron for cylinder liner and method for manufacturing cylinder liner using the same

Patent metadata

Field	Value
Publication number	US-2016108503-A1
Application number	US-201514624438-A
Country	US
Kind code	A1
Filing date	Feb 17, 2015
Priority date	Oct 16, 2014
Publication date	Apr 21, 2016
Grant date	—

Abstract

A gray cast iron for a cylinder liner is provided that maintains fatigue strength and thermal shock property by adjusting component contents. The gray cast iron includes carbon (C) in an amount of about 3.2 to 3.7 weight % (wt %); silicon (Si) in an amount of about 2.0 to 2.8 wt %; manganese (Mn) in an amount of about 0.50 to 1.0 wt %; phosphorus (P) in an amount of about 0.20 wt % or less, and greater than about 0 wt %; sulfur (S) in an amount of about 0.10 wt % or less, and greater than about 0 wt %; chromium (Cr) in an amount of about 0.50 wt % or less, and greater than about 0 wt %; copper (Cu) in an amount of about 0.20 to 0.80 wt %; molybdenum (Mo) in an amount of about 0.10 to 0.40 wt %; and the balance of iron (Fe), based on the total weight of the gray cast iron.

First claim

What is claimed is:

1 . A gray cast iron for a cylinder liner, comprising:
carbon (C) in an amount of about 3.2 to 3.7 weight % (wt %) based on the total weight of the gray cast iron; silicon (Si) in an amount of about 2.0 to 2.8 wt % based on the total weight of the gray cast iron; manganese (Mn) in an amount of about 0.50 to 1.0 wt % based on the total weight of the gray cast iron; phosphorus (P) in an amount of about 0.20 wt % or less, and greater than about 0 wt % based on the total weight of the gray cast iron; sulfur (S) in an amount of about 0.10 wt % or less, and greater than about 0 wt % based on the total weight of the gray cast iron; chromium (Cr) in an amount of about 0.50 wt % or less, and greater than about 0 wt % based on the total weight of the gray cast iron; copper (Cu) in an amount of about 0.20 to 0.80 wt % based on the total weight of the gray cast iron; molybdenum (Mo) in an amount of about 0.10 to 0.40 wt % based on the total weight of the gray cast iron; and the balance of iron (Fe), wherein the gray cast iron satisfies the following Equation 1,
0.8≦Cu+1.5Cr+1.2Mo≦1.5  [Equation 1]

where Cu, Cr, and Mo respectively mean the contents in wt % of Cu, Cr and Mo components.

2 . The gray cast iron of claim 1 , wherein the gray cast iron has a tensile strength of about 300 MPa or greater.

3 . The gray cast iron of claim 1 , wherein the gray cast iron has a fatigue strength of about 140 MPa or greater.

4 . The gray cast iron of claim 1 , consisting essentially of:
carbon (C) in an amount of about 3.2 to 3.7 weight % (wt %) based on the total weight of the gray cast iron; silicon (Si) in an amount of about 2.0 to 2.8 wt % based on the total weight of the gray cast iron; manganese (Mn) in an amount of about 0.50 to 1.0 wt % based on the total weight of the gray cast iron; phosphorus (P) in an amount of about 0.20 wt % or less, and greater than about 0 wt % based on the total weight of the gray cast iron; sulfur (S) in an amount of about 0.10 wt % or less, and greater than about 0 wt % based on the total weight of the gray cast iron; chromium (Cr) in an amount of about 0.50 wt % or less, and greater than about 0 wt % based on the total weight of the gray cast iron; copper (Cu) in an amount of about 0.20 to 0.80 wt % based on the total weight of the gray cast iron; molybdenum (Mo) in an amount of about 0.10 to 0.40 wt % based on the total weight of the gray cast iron; and the balance of iron (Fe).

5 . A method for manufacturing a cylinder liner, comprising:
manufacturing a molten steel comprising carbon (C) in an amount of about 3.2 to 3.7 weight % (wt %); silicon (Si) in an amount of about 2.0 to 2.8 wt %; manganese (Mn) in an amount of about 0.50 to 1.0 wt %; phosphorus (P) in an amount of about 0.20 wt % or less, and greater than about 0 wt %; sulfur (S) in an amount of about 0.10 wt % or less, and greater than about 0 wt %; chromium (Cr) in an amount of about 0.50 wt % or less, and greater than about 0 wt %; copper (Cu) in an amount of about 0.20 to 0.80 wt %; molybdenum (Mo) in an amount of about 0.10 to 0.40 wt %; and the balance of iron (Fe), based on the total weight of the gray cast iron; and casting the molten steel by centrifugal casting, wherein the components of the molten steel satisfy the following Equation 1,
0.8≦Cu+1.5Cr+1.2Mo≦1.5  [Equation 1]

where Cu, Cr, and Mo respectively mean the contents in wt % of Cu, Cr and Mo components.

6 . The method of claim 5 , wherein after the centrifugal casting of the molten steel, the cylinder liner has a tensile strength of about 300 MPa or greater.

7 . The method of claim 5 , wherein after the centrifugal casting of the molten steel, the cylinder liner has a fatigue strength of about 140 MPa or greater.

8 . A vehicle part that is manufactured from a gray casting iron of claim 1 .

Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp

Inventors

• Nam Duk Hyun

Classifications

• C22C37/10

  containing aluminium or silicon · CPC title

• C22C37/06 Primary

  containing chromium · CPC title

• B22D13/02

  of elongated solid or hollow bodies, e.g. pipes, in moulds rotating around their longitudinal axis · CPC title

• C22C33/08

  Making cast-iron alloys · CPC title

• B22D13/00

  Centrifugal casting; Casting by using centrifugal force · CPC title