Steel plate for high temperature applications having excellent strength at high temperature and method for manufacturing the same
AssigneePosco
InventorSoon-Taik Hong
Life of this patent
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Abstract
Provided are a steel plate for high temperature applications having excellent strength at a high temperature and a method for manufacturing same. The steel plate for high temperature applications having excellent post-weld heat treatment resistance, according to the present invention, comprises by weight percent: C:0.05-0.25%; Mn:0.1-1.0%; Si:0.1-0.8%; Cr:1-3%; Cu:0.05-0.3%; Mo:0.5-1.5%; Ni:0.05-0.5%; Al:0.005-0.1%; and at least one of Ir:0.005-0.10% and Rh:0.005-0.10%, the balance being Fe and inevitable impurities.
Claims7
A steel plate for high temperature applications having excellent post weld heat treatment (PWHT) resistance, comprising:
- by wt %, 0.05 to 0.25% of C, 0.1 to 1.0% of Mn, 0.1 to 0.8% of Si, 1 to 3% of Cr, 0.05 to 0.3% of Cu, 0.5 to 1.5% of Mo, 0.05 to 0.5% of Ni, 0.005 to 0.1% of Al, one or more of 0.005 to 0.10% of Ir and 0.005 to 0.10% of Rh, a balance of Fe, and inevitable impurities.
A method for manufacturing a steel plate for high temperature applications having excellent PWHT resistance, comprising:
- a process of reheating a steel slab to a temperature range of 1000 to 1250° C. and then hot rolling the steel slab, the steel slab comprising, by wt %, 0.05 to 0.25% of C, 0.1 to 1.0% of Mn, 0.1 to 0.8% of Si, 1 to 3% of Cr, 0.05 to 0.3% of Cu, 0.5 to 1.5% of Mo, 0.05 to 0.5% of Ni, 0.005 to 0.1% of Al, one or more of 0.005 to 0.10% of Ir and 0.005 to 0.10% of Rh, a balance of Fe, and inevitable impurities;
- a heat treatment process of maintaining the hot-rolled steel plate in a temperature range of 900 to 1000° C. for a time of 2.5×t+(10 to 30 minutes) (where, t refers to a thickness (mm) of the steel plate);
- a process of cooling the heat-treated steel plate at a cooling rate of 0.2 to 30° C./s;
- and
- a tempering heat treatment process of maintaining the cooling-controlled steel plate in a temperature range of 700 to 750° C. for a time of 2.5×t+(10 to 30 minutes) where, t refers to the thickness (mm) of the steel plate.
Dependencies are inferred from the claim text.