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US 8,691,029 B2Granted
Reduced ferrite steel liner
AssigneeCaterpillar Inc.
InventorMatthew T. Kiser
Life of this patent
Estimating the term…
Abstract
A steel liner with a case comprising at least 95% martensite, such as substantially 100% martensite, and a core comprising pearlite and discrete ferrite grains decorating former austenite grain boundaries. The ferrite in the liner's core has an average size of less than about 25 μm.
Claims19
A steel piston liner, comprising:
- a cylindrical, hollow steel body, the steel body including a cylindrical inner case disposed concentrically within and connected to a cylindrical outer core,
- the inner case being at least 95% martensite and the outer core including pearlite with discrete ferrite grains decorating former austenite boundaries,
- wherein the ferrite in the outer core has an average grain size of less than about 25 μm.
A steel piston liner, comprising:
- a cylindrical, hollow steel body including a cylindrical inner case disposed concentrically within and connected to a cylindrical outer core, the inner case being substantially 100% martensite, the inner case having a radially inner surface having a surface area, the outer core including pearlite with discrete ferrite grains decorating former austenite boundaries;
- wherein the ferrite in the outer core has an average grain size of less than 25 μm;
- wherein the inner case has a thickness of between about 0.1 and about 0.7 mm;
- and
- wherein the inner case has a hardness of at least 55 HRC over at least 95% of the surface area of inner surface the inner case.
2 more elements
Dependencies are inferred from the claim text.