Cast iron alloy for automotive engine applications with superior high temperature oxidation properties

1. A cast iron alloy with a composition in weight percent (wt. %) comprising:

carbon between 2.6 to 3.4 wt. %;

silicon between 2.4 to 3.2 wt. %;

manganese between 0.3 to 0.6 wt. %;

molybdenum between 0.4 to 1.2 wt. %;

nickel between 0.6 to 1.75 wt. %;

magnesium between 0.01 to 0.075 wt. %;

aluminum between 1.8 to 3.5 wt. %;

sulfur between 0.003 to 0.025 wt. %;

microalloyinq elements consisting of:

zirconium between 0.001 to 0.02 wt. %;

cerium between 0.001 to 0.03 wt. %; and

lanthanum between 0.0005 to 0.02 wt. %; and

a balance of iron and unavoidable trace elements.

2. The cast iron alloy according to claim 1 , wherein at least one of carbon is between 2.8 to 3.2 wt. % and silicon is between 2.6 to 3.2 wt. %.

3. The cast iron alloy according to claim 1 , wherein manganese is between 0.32 to 0.5 wt. %.

4. The cast iron alloy according to claim 1 , wherein at least one of molybdenum is between 0.6 to 1.0 wt. % and nickel is between 0.8 to 1.5 wt. %.

5. The cast iron alloy according to claim 1 , wherein magnesium is between 0.02 to 0.05 wt. %.

6. The cast iron alloy according to claim 1 , wherein aluminum is between 2.0 to 3.2 wt. %.

7. The cast iron alloy according to claim 1 , wherein at least one of sulfur is between 0.005 to 0.015 wt. % and cerium is between 0.002 to 0.02 wt. %.

8. The cast iron alloy according to claim 1 , wherein lanthanum is between 0.001 to 0.02 wt. %.

9. The cast iron alloy according to claim 1 further comprising a plurality of graphite nodules formed on a lanthanum containing nuclei.

10. The cast iron alloy according to claim 9 , wherein the lanthanum containing nuclei are (La, Ce, Zr)(O, S) nuclei.

11. A part formed from the cast iron alloy according to claim 1 , wherein the part comprises an Ac1 temperature equal to or greater than 875° C.

12. The part according to claim 11 , wherein the Ac1 temperature is equal to or greater than 885° C.

13. A part formed from the cast iron alloy according to claim 1 , wherein the part comprises a thermo-mechanical fatigue lifetime of at least 10,000 cycles when cycled between 400° C. to 800° C. with a total cyclic strain equal to 0.001 m/m.

14. A part formed from the cast iron alloy according to claim 1 , wherein the part comprises a thermo-mechanical fatigue lifetime of at least 2,000 cycles when cycled between 400° C. to 800° C. with a total cyclic strain equal to 0.002 m/m.

15. The cast iron alloy according to claim 1 , wherein:

carbon is between 2.8 to 3.2 wt. %;

silicon is between 2.6 to 3.0 wt. %;

manganese is between 0.35 to 0.5 wt. %;

molybdenum is between 0.6 to 1.0 wt. %;

nickel is between 0.8 to 1.5 wt. %;

magnesium is between 0.02 to 0.05 wt. %;

aluminum is between 2.0 to 3.2 wt. %;

sulfur is between 0.005 to 0.015 wt. %;

zirconium is between 0.002 to 0.01 wt. %;

cerium is between 0.002 to 0.02 wt. %; and

lanthanum is between 0.001 to 0.01 wt. %.

16. A cast iron alloy with a composition in weight percent (wt. %) comprising:

carbon between 2.6 to 3.4 wt. %;

silicon between 2.4 to 3.2 wt. %;

manganese between 0.32 to 0.6 wt. %;

molybdenum between 0.4 to 1.2 wt. %;

nickel between 0.6 to 1.75 wt. %;

magnesium between 0.01 to 0.075 wt. %;

aluminum between 1.8 to 3.5 wt. %;

sulfur between 0.003 to 0.025 wt. %;

microalloyinq elements consisting of:

zirconium between 0.001 to 0.02 wt. %;

cerium between 0.001 to 0.03 wt. %; and

lanthanum between 0.0005 to 0.02 wt. %; and

a balance of iron and unavoidable trace elements.

17. The cast iron alloy according to claim 16 , wherein:

carbon is between 2.8 to 3.2 wt. %;

silicon is between 2.6 to 3.0 wt. %;

manganese is between 0.35 to 0.5 wt. %;

molybdenum is between 0.6 to 1.0 wt. %;

nickel is between 0.8 to 1.5 wt. %;

magnesium is between 0.02 to 0.05 wt. %;

aluminum is between 2.0 to 3.2 wt. %;

sulfur is between 0.005 to 0.015 wt. %;

zirconium is between 0.002 to 0.01 wt. %;

cerium is between 0.002 to 0.02 wt. %; and

lanthanum is between 0.001 to 0.01 wt. %.

18. A part formed from the cast iron alloy according to claim 17 , part formed from the cast iron alloy, wherein the part comprises at least one of an Ac1 temperature equal to or greater than 885° C., a thermo-mechanical fatigue lifetime of at least 10,000 cycles when cycled between 400° C. to 800° C. and a total cyclic strain equal to 0.001 m/m, and a thermo-mechanical fatigue lifetime of at least 2,000 cycles when cycled between 400° C. to 800° C. with a total cyclic strain equal to 0.002 m/m.

19. A cast iron alloy with a composition in weight percent (wt. %) comprising:

carbon between 2.6 to 3.4 wt. %;

silicon between 2.4 to 3.2 wt. %;

manganese between 0.35 to 0.5 wt. %;

molybdenum between 0.4 to 1.2 wt. %;

nickel between 0.6 to 1.75 wt. %;

magnesium between 0.01 to 0.075 wt. %;

aluminum between 1.8 to 3.5 wt. %;

sulfur between 0.003 to 0.025 wt. %;

microalloyinq elements consisting of:

zirconium between 0.001 to 0.02 wt. %;

cerium between 0.001 to 0.03 wt. %; and

lanthanum between 0.0005 to 0.02 wt. %;

balance of iron and unavoidable trace elements; and

a plurality of graphite nodules formed on (La, Ce, Zr)(O, S) nuclei.

20. A part formed from the cast iron alloy according to claim 19 , part formed from the cast iron alloy, wherein the part comprises a thermo-mechanical fatigue lifetime of at least 10,000 cycles when cycled between 400° C. to 800° C. and a total cyclic strain equal to 0.001 m/m, and a thermo-mechanical fatigue lifetime of at least 2,000 cycles when cycled between 400° C. to 800° C. with a total cyclic strain equal to 0.002 m/m.