Posco

Posco Co., Ltd

Jai-Ik Kim

Won-Ho Son

Hyun-Seok Ko

Jin-A Kim

Jong-Hwa Kim

Jeong-Bong Yoon

Seung-Hee Lee

Hee-Man Son

Min-Gwan Seong

An exemplary embodiment of the present invention provides an enamel steel sheet, including: by wt % (% by weight), 0.01 to 0.05% of C, 0.05 to 0.8% of Mn, 0.001 to 0.03% of Si, 0.03 to 0.12% of Al, 0.001 to 0.02% of P, 0.001 to 0.02% of S, 0.004% or less (excluding 0%) of N, 0.001 to 0.003% of B, 0.003% or less (excluding 0%) of O, and the balance of Fe and inevitable impurities. The enamel steel sheet according to an exemplary embodiment of the present invention includes an oxide layer in an inside direction from a surface, and a thickness of the oxide layer is 0.006 to 0.030 μm.

Steel sheet for enamel and method of manufacturing the same

Described herein is an enamel steel sheet comprising by wt %, 0.01 to 0.05% of C, 0.46 to 0.80% of Mn, 0.001 to 0.03% of Si, 0.01 to 0.08% of Al, 0.001 to 0.02% of P, 0.001 to 0.02% of S, 0.004% or less (excluding 0%) of N, 0.003% or less (excluding 0%) of O, and the balance of Fe and inevitable impurities. The enamel steel sheet may include an oxide layer from the surface to the inner direction thereof, wherein the oxide layer has a thickness of 0.006 to 0.003 μm.

Enamel steel sheet and manufacturing method therefor

The purpose of one aspect of the present disclosure is to provide: a cold rolled steel sheet for a flux-cored wire, having excellent low temperature toughness, welding workability and processability; and a manufacturing method thereof. One embodiment of the present disclosure provides: a cold rolled steel sheet for a flux-cored wire, comprising, by wt %, 0.005-0.10% of C, 0.05-0.25% of Mn, 0.05% or less of Si (excluding 0%), 0.0005-0.01% of P, 0.008% or less of S (excluding 0%), 0.005-0.06% of Al, 0.0005-0.003% of N, 0.8-1.7% of Ni, 0.1-0.5% of Cr, and a balance of Fe and inevitable impurities, and having 0.10-0.75 of WN defined by Relationship 1 below; and a manufacturing method therefor.WN=(31&#xd7;C+0.5&#xd7;Mn+20&#xd7;Al)&#xd7;(Ni)&#xd7;(0.6&#xd7;Cr).&#x2003;&#x2003;Relationship 1

Cold rolled steel sheet for flux-cored wire, and manufacturing method therefor

The present disclosure provides a cold-rolled steel sheet having excellent high-temperature properties and room-temperature workability, including, by weight: carbon (C): 0.0005 to 0.003%, manganese (Mn): 0.20 to 0.50%, aluminum (Al): 0.01 to 0.10%, phosphorus (P): 0.003 to 0.020%, nitrogen (N): 0.0005 to 0.004%, sulfur (S): 0.015% or less, niobium (Nb): 0.005 to 0.040%, chromium (Cr): 0.10 to 0.50%, tungsten (W): 0.02 to 0.07%, and a balance of iron (Fe) and other inevitable impurities, wherein C, Nb, and W satisfy the following relationship 1, a microstructure comprises 95 area % or more of polygonal ferrite and 5 area % or less of acicular ferrite, and the cold-rolled steel sheet comprises (Nb,W)C-based precipitates having an average size of 0.005 to 0.10 &#x3bc;m and a method for manufacturing the same:0.00025&#x2264;(2&#xd7;Nb/93)&#xd7;(W/184)/(C/12)&#x2264;0.0015&#x2003;&#x2003;[Relationship 1]where, C, Nb, and W are in weight %.

Cold-rolled steel sheet having excellent high-temperature properties and room-temperature workability

The present invention relates to a hot-rolled steel sheet applied as a material for home appliances, vehicles, or the like and, more specifically, to a hot-rolled steel sheet having excellent workability and anti-aging properties and a method for manufacturing the same. To this end, the present invention uses ultra-low carbon Al-killed steel so as to optimize the alloying elements thereof and the manufacturing conditions, thereby providing hot-rolled steel sheets having both excellent workability and anti-aging properties.

Hot-rolled steel having excellent workability and anti-aging properties

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&#xb0; C.

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Pohang-si, South Korea

Jai-Ik Kim