High-modulus, high-strength, low alloy gray cast iron for cylinder liners and automotive applications

1. A gray cast iron comprising:

from about 2.60 weight percent (wt %) to about 3.30 wt % Carbon (C);

from about 1.50 wt % to about 2.30 wt % Silicon (Si);

from about 0.30 wt % to about 0.80 wt % Manganese (Mn);

from about 0.15 wt % to about 0.35 wt % Phosphorus (P);

from about 0.05 wt % to about 0.11 wt % Sulphur (S);

from about 0.60 wt % to about 1.20 wt % Copper (Cu);

from about 0.10 wt % to about 0.30 wt % Chromium (Cr);

from greater than 0.0 wt % to 0.1 wt % Nickle (Ni);

from about 0.15 wt % to about 0.40 wt % Molybdenum (Mo); and

balance wt % Iron (Fe);

a Carbon Equivalent (CE) from about 3.00 wt % to 3.90 wt %, wherein CE=C+[1/3(Si+P)];

wherein Si, Mn, P, S Cu, Cr, Ni, and Mo includes a total weight percent from about 4.00 wt % to 4.20 wt %;

wherein Mn %*S % is from about 0.025 to about 0.045;

wherein the gray cast iron casting alloy is a cylinder liner obtained by centrifugal casting, comprising:

a modulus of elasticity from about 137 Gpa to about 143 Gpa; and

an ultimate tensile strength from about 330 Mpa to about 380 Mpa.

2. The gray cast iron of claim 1 , wherein the CE is about 3.76 wt %.

3. The gray cast iron of claim 1 , wherein Mn %*S % is about 0.04.

4. The gray cast iron of claim 1 , having an Ultimate Tensile Strength (Mpa) to an Alloying Elements total weight percent (total wt %) ratio of greater than 80 Mpa/total wt %, wherein the total wt % is a total weight percent of Si, Mn, P, S Cu, Cr, Ni, and Mo.

5. The gray cast iron of claim 1 having a microstructure comprising a eutectic cell count of from about 3500/cm 2 to about 4900/cm 2 .

6. The gray cast iron of claim 5 , wherein the microstructure comprises a plurality of graphite flakes, wherein greater than 50% of the plurality of graphite flakes are 40-80 microns in length.

7. The gray cast iron of claim 6 , wherein greater than 90% of the plurality of graphite flakes are Graphite Type A flakes.

8. A gray cast iron cylinder liner comprising:

from about 2.60 weight percent (wt %) to about 3.30 wt % Carbon (C);

from about 1.50 wt % to about 2.30 wt % Silicon (Si);

from about 0.30 wt % to about 0.80 wt % Manganese (Mn);

from about 0.15 wt % to about 0.35 wt % Phosphorus (P);

from about 0.05 wt % to about 0.11 wt % Sulphur (S);

from about 0.60 wt % to about 1.20 wt % Copper (Cu);

from about 0.10 wt % to about 0.30 wt % Chromium (Cr);

from greater than 0.0 wt % to 0.1 wt % Nickle (Ni);

from about 0.15 wt % to about 0.40 wt % Molybdenum (Mo); and

balance wt % Iron (Fe); and wherein

Mn %*S % is from about 0.025 to about 0.045, and

Carbon Equivalent (CE)=C+[1/3(Si+P)] is from about 3.00 wt % to 3.90 wt %;

wherein the gray cast iron cylinder liner is a centrifugally cast cylinder liner, comprising:

a modulus of elasticity from about 137 GPa to about 143 GPa; and

an ultimate tensile strength from about 330 MPa to about 380 MPa.

9. The gray cast iron cylinder liner of claim 8 , wherein:

C is about 3.00 wt %;

Si is about 2.00 wt %;

Mn is about 0.48 wt %;

P is about 0.25 wt %;

S is about 0.08 wt %;

Cu is about 0.87 wt %;

Cr is about 0.10 wt %;

Ni is about 0.1 wt %;

Mo is about 0.22 wt %;

CE is about 3.76 wt %; and

Mn %*S % is about 0.04.

10. The gray cast iron cylinder liner of claim 8 , wherein Si, Mn, P, S Cu, Cr, Ni, and Mo includes a total weight percent from about 4.00 wt % to 4.20 wt %.

11. The gray cast iron cylinder liner of claim 8 , further comprises less than 1 wt % carbide.

12. The gray cast iron cylinder liner of claim 8 , further includes a microstructure comprising a eutectic cell count of from about 3500/cm 2 to about 4900/cm 2 .

13. The gray cast iron cylinder liner of claim 12 , wherein the microstructure comprises greater than 90% Graphite Type A and greater than 50% Size 5 Graphite flakes.

14. A gray iron casting alloy comprising:

from about 2.60 weight percent (wt %) to about 3.30 wt % Carbon (C);

from about 1.50 wt % to about 2.30 wt % Silicon (Si);

from about 0.30 wt % to about 0.80 wt % Manganese (Mn);

from about 0.15 wt % to about 0.35 wt % Phosphorus (P);

from about 0.05 wt % to about 0.11 wt % Sulphur (S);

from about 0.60 wt % to about 1.20 wt % Copper (Cu);

from about 0.10 wt % to about 0.30 wt % Chromium (Cr);

from greater than 0.0 wt % to about 0.1 wt % Nickle (Ni);

from about 0.15 wt % to about 0.40 wt % Molybdenum (Mo); and

balance Iron (Fe); and

wherein Mn %*S % is from about 0.025 to about 0.045;

wherein the gray iron casting alloy is a centrifugal cast cylinder liner comprising a microstructure comprising a plurality of graphite flakes, wherein greater than 50% of the plurality of graphite flakes are 40-80 microns in length.

15. The gray iron casting alloy of claim 14 , wherein Si, Mn, P, S Cu, Cr, Ni, and Mo includes a total weight percent from about 4.00 wt % to 4.20 wt %.

16. The gray iron casting alloy of claim 15 , wherein:

C is about 3.00 wt %;

Si is about 2.00 wt %;

Mn is about 0.48 wt %;

P is about 0.25 wt %;

S is about 0.08 wt %;

Cu is about 0.87 wt %;

Cr is about 0.10 wt %;

Ni is about 0.1 wt %; and

Mo is about 0.22 wt %.

17. The gray iron casting alloy of claim 16 , wherein Mn %*S % is about 0.04.

18. The gray iron casting alloy of claim 14 , further comprising a Carbon Equivalent (CE) from about 3.00 wt % to 3.90 wt %, wherein CE=C+[1/3(Si+P)].

19. The gray iron casting alloy of claim 18 , wherein the CE is about 3.76 wt %.

20. The gray iron casting alloy of claim 14 , wherein the centrifugal cast cylinder liner includes:

a modulus of elasticity from about 137 Gpa to about 143 Gpa; and

an ultimate tensile strength from about 330 Mpa to about 380 Mpa.