Plastic injection mold of low carbon martensitic stainless steel
AssigneeEdro Specialty Steels, Inc.
InventorsKristopher D Welch, Robert J. Friedrich, Eric D. Henn, Michael A. Guscott
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Abstract
A mold plate having a mold cavity configured for plastic injection molding one or more articles such as a panel or frame of an electronic display screen such as a flat screen TV is formed from a low carbon martensitic stainless steel alloy comprising: about 0.05%-0.07% by weight C, about 1.15%-1.45% by weight Mn, a maximum of 0.025% by weight P, a maximum of 0.008% by weight S, about 0.3%-0.6% by weight Si, about 12.15%-12.65% by weight Cr, about 0%-0.5% by weight Ni, about 0.45%-0.65% by weight Cu, about 0.02%-0.08% by weight V, about 0.04%-0.08% by weight N, with the balance being Fe with trace amounts of ordinarily present elements.
Claims22
A mold plate for plastic injection having a highly polished mold surface shaped for articles including frames or panels of electronic display screens, the mold plate being formed from a molybdenum-free low carbon martensitic stainless steel alloy comprising in weight %:
- about 0.05 to 0.07% C;
- about 1.15 to 1.45% Mn;
- about 0 to 0.025% P;
- about 0 to 0.008% S;
- about 0.45 to 0.6% Si;
- about 12.15 to 12.65% Cr;
- about 0 to 0.5% Ni;
- about 0.45 to 0.65% Cu;
- about 0.02 to 0.08% V;
- about 0.04 to 0.08% N;
- the balance being Fe with trace amounts of impurities and the alloy has a Rockwell C hardness (HRC) within the range of 38 to 42 HRC.
A low carbon martensitic stainless steel alloy in an as-rolled, air-cooled and optionally age hardened condition adapted for use in the manufacture of plastic injection mold plates, the alloy being molybdenum-free and comprising about 1.15%-1.45% by weight Mn, a maximum of 0.025% by weight P, about 0.45%-0.6% by weight Si, about 12.15%-12.65% by weight Cr, a maximum of 0.5% by weight Ni, about 0.45%-0.65% by weight Cu, about 0.02%-0.08% by weight V, about 0.04%-0.08% by weight N, a maximum of 0.008% by weight S, 0.05% to 0.07% by weight C and the balance being Fe with residual impurities wherein the alloy has a Rockwell C hardness (HRC) within the range of 38 to 42 HRC.
Dependencies are inferred from the claim text.