Method of making a heat treated steel casting and a heat treated steel casting
AssigneeNACO, Inc.
InventorPaul Herbert Hewitt
Life of this patent
Estimating the term…
Abstract
A method of making a heat treated steel casting comprising the steps of taking an "as-cast" steel casting comprising not more than 0.2% carbon, a total alloy content of less than about 4%, a carbon equivalent, as herein defined, lying in the range 0.45-0.7 and cooling the casting after performing the casting operation and then performing a heat treatment operation by re-heating the casting to a temperature above the AC.sub.3 temperature to homogenize the casting, then cooling the casting to an inter-critical temperature lying between the AC.sub.3 and AC.sub.1 temperature and then quenching to room temperature.
Claims27
A method of making a heat treated steel casting comprising the steps of performing a casting operation to make an "as-cast" steel casting comprising not more than 0.2% carbon, a total alloy content of less than about 4%, a carbon equivalent, as herein defined, lying in the range 0.45-0.7% and cooling the casting after performing the casting operation and then performing a heat treatment operation by re-heating the casting to a temperature above the AC.sub.3 temperature to homogenize the casting without any intervening step between said casting operation and said heat treatment operation other than said step of cooling subsequent to casting, then cooling the casting to an inter-critical temperature lying between the AC.sub.3 and AC.sub.1 temperature and then quenching to room temperature.
A method according to claim 9 wherein the casting comprises 0.15% to 0.20% carbon.
A method of making a heat treated steel casting comprising the steps of taking an "as-cast" steel casting wherein the casting comprises a steel comprising
- C 0.1-0.2%
- Mn 0.9-1.5%
- S 0.002-0.015%
- P 0.002-0.015%
- Mo 0-0.2%
- Ni 0.3-0.6%
- Cr 0.3-0.6%
- Nb 0-0.19%
- Ti 0.02-0.10%
- Cu 0.5-1.0%
- V 0.10-0.19%
- Al 0.03-0.14%
- W 0.10-0.5%
- Si 0.30-0.65%
- N.sub.2 0.008-0.012%
- O.sub.2 0.006-0.025%
- H.sub.2 0.0003-0.0006%
- Fe and
- Usual Residuals Balance,
- cooling the casting after performing the casting operation, performing a heat treatment operation by re-heating the casting to a temperature above the AC.sub.3 temperature to homogenize the casting, cooling the casting to an inter-critical temperature lying between the AC.sub.3 and AC.sub.1 temperature, and quenching to room temperature.
A heat treated steel casting comprising not more than 0.2% carbon, a total alloy content of less than about 4%, a carbon equivalent, as herein defined, lying in the range 0.45 to 0.7% and which has been heat treated, after casting and then cooling, by re-heating the casting to a temperature above the AC.sub.3 temperature to homogenize the casting without any intervening step between said casting and said re-heating other than said step of cooling subsequent to casting, then cooling the casting to a intercritical temperature lying between the AC.sub.3 and AC.sub.1 temperature and then quenching to room temperature.
A heat treated steel casting comprising:
- C 0.1-0.2%
- Mn 0.9-1.5%
- S 0.002-0.015%
- P 0.002-0.015%
- Mo 0-0.2%
- Ni 0.3-0.6%
- Cr 0.3-0.6%
- Nb 0-0.1%
- Ti 0.02-0.10%
- Cu 0.5-1.0%
- V 0.10-0.19%
- Al 0.03-0.14%
- W 0.10-0.5%
- Si 0.30-0.65%
- N.sub.2 0.008-0.012%
- O.sub.2 0.006-0.025%
- H.sub.2 0.0003-0.0006%
- Fe and
- Usual
- Residuals Balance
- and which has been heat treated, after casting and then cooling, by re-heating the casting to a temperature above the AC.sub.3 temperature to homogenize the casting, then cooling the casting to an inter-critical temperature lying between the AC.sub.3 and AC.sub.1 temperature and then quenching to room temperature.
Dependencies are inferred from the claim text.