CPC C22C 38/44 (2013.01) [B32B 15/012 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C23C 4/10 (2013.01); C23C 4/131 (2016.01)] | 10 Claims |
1. A cylinder block comprising:
a cylinder bore having an inner peripheral surface; and
a spray coating disposed on the inner peripheral surface of the cylinder bore; wherein:
the cylinder block is made of aluminum or an aluminum alloy;
the spray coating contains:
0.005% to 0.07% by mass of carbon,
0.01% to 3.0% by mass of nickel,
10% to 15.5% by mass of chromium,
0.05% to 1.5% by mass of silicon, and
a balance containing iron and inevitable impurities;
the spray coating has a composition that forms a martensite+ferrite region in a Schaeffler diagram, and in which a nickel equivalent (NiE) and a chromium equivalent (CrE) in the Schaeffler diagram satisfy a relationship expressed by the following Formulae (1) to (3)
NiE≤0.95CrE−8.59 (1),
NiE≤4.1 (2), and
CrE≥10 (3);
the spray coating has a two-phase structure formed of a martensite phase and a ferrite phase; and
the spray coating has a surface porosity of 2.7% or less.
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