Low alloy steel plastic injection mold base plate, method of manufacture and use thereof
OwnerEric D. Henn, Robert J. Friedrich +2inventors
InventorsEric D. Henn, Robert J. Friedrich, Michael A. Guscott, Terry O. Henn
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Abstract
A hot worked low alloy tool steel plate can be machined into mold base parts useful for holding tooling used in plastic injection molding. The tool steel alloy preferably exhibits desired strength, toughness, ductility, weldability, uniform hardness and dimensional stability. A process for manufacture of the steel plate includes hot working, hot roller leveling, air cooling and tempering to desired hardness.
Claims27
A mold base plate useful as plastic injection mold base parts formed of a hot worked boron-free tool steel alloy plate which has been manufactured by hot working, hot leveling after the hot working, air cooling after the hot leveling until complete transformation of the microstructure occurs, and tempering after the air cooling to lower hardness of the plate to below about 320 BHN, the tool steel alloy comprising:
- about 0.21 percent to about 0.28 percent by weight carbon;
- about 0.6 percent to about 0.9 percent by weight manganese;
- a maximum of 0.02 percent by weight phosphorous;
- from about 0.02 to about 0.1 percent by weight sulfur;
- from about 0.25 percent to about 0.5 percent by weight silicon;
- from about 1.7 percent to about 2.2 percent by weight chromium;
- a maximum of 0.35 percent by weight nickel;
- a maximum of 0.4 percent by weight copper;
- up to about 0.2 percent by weight molybdenum;
- from about 0.015 percent to about 0.05 percent by weight aluminum;
- and the balance being iron with up to 0.5 percent by weight total of other elements.
A hot worked and tempered mold base plate of a boron-free tool steel alloy, the tool steel alloy being comprised of from about 0.21 percent to about 0.28 percent by weight carbon, from about 0.6 percent to about 0.9 percent by weight manganese, a maximum of 0.02 percent by weight phosphorous, from about 0.02 to about 0.1 percent by weight sulfur, from about 0.25 percent to about 0.45 percent by weight silicon, from about 1.7 percent to about 2.2 percent by weight chromium, a maximum of 0.35 percent by weight nickel, a maximum of 0.4 percent by weight copper, up to about 0.2 percent by weight molybdenum, from about 0.015 percent to about 0.05 percent by weight aluminum and the balance being iron with up to 0.5 percent by weight total of other elements wherein the alloy has a hardness within the range of from about 270 to about 320 BHN.
A hot worked and tempered mold base plate of a boron-free tool steel alloy, the tool steel alloy consisting essentially of from about 0.21 percent to about 0.28 percent by weight carbon, from about 0.6 percent to about 0.9 percent by weight manganese, a maximum of 0.02 percent by weight phosphorous, from about 0.02 to about 0.1 percent by weight sulfur, from about 0.25 percent to about 0.5 percent by weight silicon, from about 1.7 percent to about 2.2 percent by weight chromium, a maximum of 0.35 percent by weight nickel, a maximum of 0.4 percent by weight copper, up to about 0.2 percent by weight molybdenum, from about 0.015 percent to about 0.05 percent by weight aluminum and the balance being iron with up to 0.5 percent by weight total of other elements wherein the alloy has a hardness within the range of from about 270 to about 320 BHN.
Dependencies are inferred from the claim text.