Knobbe Martens Olson & Bear, LLP
Quenchable steel sheet having high hot press workability and method of manufacturing the same
The quenchable steel sheet has an alloy composition including carbon (C) in an amount of 0.15˜0.30 wt %, silicon (Si) in an amount of 0.05˜0.5 wt %, manganese (Mn) in an amount of 1.0˜2.0 wt %, boron (B) in an amount of 0.0005˜0.0040 wt %, sulfur (S) in an amount of 0.003 wt % or less, phosphorus (P) in an amount of 0.012 wt % or less, one or more selected from among calcium (Ca) in an amount of 0.0010˜0.0040 wt % and copper (Cu) in an amount of 0.05˜1.0 wt %, two or more selected from among cobalt (Co), zirconium (Zr) and antimony (Sb), and iron (Fe). Alloy elements are controlled to increasing hot ductility and enabling pressing at 600˜900° C. so that a tensile strength of 1400 MPa or more and an elongation of 8% or more are obtained after pressing.
Hyundai Steel Company
C Y C C C
C22C Y10T C22C C22C C22C
inventional additional inventional inventional inventional
Seongju Taekjoon Seungha
Kim Kim Lee