Corrosion and wear resistant iron based alloy useful for internal combustion engine valve seat inserts and method of making and use thereof

1. An iron-based alloy having a copper precipitation strengthening mechanism comprising, in weight percentage:

carbon from about 1.6 to 3.0%;

silicon from about 0.8 to 2.1%;

manganese up to 1.0%;

chromium from about 12.0 to 15.0%;

molybdenum from about 2.0 to 4.0%;

nickel from about 0.2 to 0.8%;

copper from about 0.4 to 4.0%;

phosphorus from about 0.005 to about 0.015%;

boron from about 0.15 to 0.5%; and

balance iron and incidental impurities;

wherein the alloy has a microstructure comprising tempered martensite.

2. The alloy of claim 1 , further comprising:

sulfur from about 0.005 to 0.01%;

nitrogen up to about 0.5%; and

iron from about 74.0 to 81.0%.

3. The alloy of claim 1 , comprising, in weight percentage:

carbon from about 1.8 to 2.2%;

silicon from about 0.8 to 1.2%;

manganese from about 0.3 to 0.6%;

chromium from about 13.0 to 14.0%;

molybdenum from about 2.1 to 2.5%;

nickel from about 0.2 to 0.5%;

copper from about 0.4 to 2.0%;

boron from about 0.15 to 0.2%; and

balance iron and incidental impurities.

4. The alloy of claim 1 , wherein the alloy is vanadium-free, titanium-free, niobium free, tantalum-free, and/or tungsten-free.

5. The alloy of claim 1 , wherein the alloy is vanadium-free, titanium-free, niobium-free, tantalum-free, and tungsten-free.

6. The alloy of claim 1 , wherein the alloy is in a hardened and tempered condition having a hardness of at least about 45 to about 50 Rockwell C.

7. The alloy of claim 1 , wherein the alloy is in a hardened and tempered condition and exhibits a Vickers hot hardness at a temperature of 800° F. of at least about 415.

8. The alloy of claim 1 , wherein the alloy is in a hardened and tempered condition and exhibits a high temperature compressive yield strength at 800° F. of at least about 100 ksi.

9. A part for an internal combustion engine comprising the alloy of claim 1 .

10. A valve seat insert comprising the alloy of claim 1 .

11. A valve seat insert for use in an internal combustion engine, said valve seat insert made of an iron-based alloy comprising, in weight percent:

carbon from about 1.6 to 3.0%;

silicon from about 0.8 to 2.1%;

manganese up to 1.0%;

chromium from about 12.0 to 15.0%;

molybdenum from about 2.0 to 4.0%;

nickel from about 0.2 to 0.8%;

copper from about 0.4 to 4.0%;

phosphorus from about 0.005 to about 0.015%;

boron from about 0.15 to 0.5%, and

balance iron and incidental impurities;

wherein the alloy has a microstructure comprising tempered martensite.

12. A method of manufacturing the valve seat insert of claim 11 , comprising casting the iron-based alloy and machining a piece of the iron-based alloy.

13. A method of manufacturing the valve seat insert of claim 11 , comprising compacting powder of the iron-based alloy into a shaped piece and sintering the shaped piece of the iron-based alloy.

14. A method of manufacturing an internal combustion engine comprising inserting the valve seat insert of claim 11 in a cylinder head of the internal combustion engine.

15. A valve seat insert for a diesel engine comprising the alloy of claim 1 .

16. A valve seat insert for a diesel engine using EGR comprising the alloy of claim 1 .

17. A valve seat insert comprising the alloy of claim 1 , wherein the valve seat insert is in the form of a casting.

18. A valve seat insert comprising the alloy of claim 1 , wherein the valve seat insert is in the form of a pressed and sintered compact.

19. A method of manufacturing the valve seat insert of claim 11 , comprising machining a piece of the iron-based alloy.

20. A method of manufacturing an internal combustion engine comprising inserting the valve seat insert of claim 11 in a cylinder head of the internal combustion engine.

21. The method of claim 20 , wherein the engine is a diesel or natural gas engine.

22. A method of operating an internal combustion engine comprising closing a valve against the valve seat insert of claim 11 to close a cylinder of the internal combustion engine and igniting fuel in the cylinder to operate the internal combustion engine.