Finnegan, Henderson, Farabow, Garrett & Dunner, L.L.P.
Corrosion resistance improved steel sheet for automotive muffler and method of producing the steel sheet
Provided are a steel sheet for an automotive muffler and a method for producing the steel sheet. The steel sheet includes 0.01% by weight or less of C, 0.1 to 0.3% by weight of Si, 0.3 to 0.5% by weight of Mn, 0.015% by weight or less of P, 0.015% or less by weight of S, 0.02 to 0.05% by weight of Al, 0.004% or less of N, 0.2 to 0.6% by weight of Cu, 0.01 to 0.04% by weight of Co, and a remainder of Fe and unavoidable impurities. The method includes 0.01% by weight or less of C, 0.1 to 0.3% by weight of Si, 0.3 to 0.5% by weight of Mn, 0.015% by weight or less of P, 0.015% or less by weight of S, 0.02 to 0.05% by weight of Al, 0.004% or less of N, 0.2 to 0.6% by weight of Cu, 0.01 to 0.04% by weight of Co, and a remainder of Fe and unavoidable impurities, preparing a hot rolled steel sheet by re-heating the steel slab and by, during a finish rolling process, hot-rolling the steel slab at a temperature that is an Ar3 transformation temperature or more, preparing a cold rolled steel sheet by cold-rolling the hot rolled steel sheet with a cold reduction ratio of 50 to 90%, and performing a continuous annealing for the cold rolled steel sheet at a temperature of 500 to 900° C.
Posco
C C C C C C C
C22C C22C C22C C22C C22C C22C C22C
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Jeong-Bong Jai-Ik Hee-Man Won-Ho Seung-Hee
Yoon Kim Son Son Lee