Iron-based alloys and methods of making and use thereof

An iron-based alloy comprising, in weight percent:

• carbon from about 1 to about 2 percent;
• manganese up to about 1 percent;
• silicon up to about 1 percent;
• molybdenum from about 5 to about 20 percent;
• cobalt from about 17 to about 23 percent;
• boron up to about 0.2 percent;
• sulfur up to about 0.03 percent;
• phosphorus up to about 0.06 percent;
• iron from about 35 to about 55 percent;
• niobium from about 0.1 to about 0.2 percent;
• tungsten up to about 0.25 percent;
• vanadium from about 0.01 to about 0.05 percent;
• nitrogen from about 0.1 to about 0.25 percent;
• nickel up to about 0.6 percent;
• and chromium from about 13 to about 19 percent;
• and incidental impurities;
• wherein the chromium/molybdenum ratio of the iron-based alloy is from about 1 to about 2.5.

An iron-based alloy comprising, in weight percent:

• carbon from about 1 to about 2 percent;
• manganese up to about 1 percent;
• silicon up to about 1 percent;
• nickel up to about 4 percent;
• chromium from about 10 to about 25 percent;
• molybdenum from about 5 to about 20 percent;
• tungsten up to about 4 percent;
• cobalt from about 17 to about 23 percent;
• vanadium up to about 1.5 percent;
• boron 0.03 to about 0.2 percent;
• sulfur up to about 0.03 percent;
• nitrogen up to about 0.4 percent;
• phosphorus up to about 0.06 percent;
• niobium up to about 4 percent;
• iron from about 35 to about 55 percent;
• and incidental impurities;
• wherein the chromium/molybdenum ratio of the iron-based alloy is from about 1 to about 2.5.

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

• carbon from about 1.6 to about 2 percent;
• manganese up to about 1 percent;
• silicon up to about 1 percent;
• nickel up to about 4 percent;
• chromium from about 10 to about 25 percent;
• molybdenum from about 5 to about 20 percent;
• tungsten up to about 4 percent;
• cobalt from about 17 to about 23 percent;
• vanadium up to about 1.5 percent;
• boron up to about 0.2 percent;
• sulfur up to about 0.03 percent;
• nitrogen up to about 0.4 percent;
• phosphorus up to about 0.06 percent;
• niobium up to about 4 percent;
• iron from about 35 to about 55 percent;
• and incidental impurities;
• wherein the chromium/molybdenum ratio of the iron-based alloy is from about 1 to about 2.5.

A method of manufacturing a valve seat insert, the method comprising:

• preparing an iron-based alloy comprising, in weight percent:
• carbon from about 1.6 to about 2 percent;
• manganese up to about 1 percent;
• silicon up to about 1 percent;
• nickel up to about 4 percent;
• chromium from about 10 to about 25 percent;
• molybdenum from about 5 to about 20 percent;
• tungsten up to about 4 percent;
• cobalt from about 17 to about 23 percent;
• vanadium up to about 1.5 percent;
• boron up to about 0.2 percent;
• sulfur up to about 0.03 percent;
• nitrogen up to about 0.4 percent;
• phosphorus up to about 0.06 percent;
• niobium up to about 4 percent;
• iron from about 35 to about 55 percent;
• and incidental impurities, wherein the chromium/molybdenum ratio of the iron-based alloy is from about 1 to about 2.5;
• heat treating the iron-based alloy at a temperature of from about 1500° F. to about 1700° F.;
• and tempering the iron-based alloy at a temperature of from about 600° F. to about 1500° F.