WELDABLE HIGH-TENSILE STEEL EXCELLENT IN LOW-TEMPERATURE TOUGHNESS,申请号EP19960901129-传众专利搜索

WELDABLE HIGH-TENSILE STEEL EXCELLENT IN LOW-TEMPERATURE TOUGHNESS

申请公布号：EP0753596(A4)

申请号：EP19960901129

申请日期：1996.01.26

申请公布日期：1998.05.20

申请人：

NIPPON STEEL CORPORATION

发明人：CAMEHIRO, HIROSHI;ASAHI, HITOSHI;HARA, TAKUYA;TERADA, YOSHIO

分类号：C21D8/02;C22C38/04

主分类号：C21D8/02

摘要：This invention adds elements such as Cu, B, Cr, Ca, V, etc., to a low carbon-high Mn-Ni-Mo-trace Ti type steel, and allows the steel to have a tempered martensite/bainite mixed structure containing at least 60% of tempered martensite transformed from un-recrystallized austenite having a mean austenite grain size (d gamma ) of not greater than 10 mu m as a micro-structure, or a tempered martensite structure containing at least 90% of martensite transformed from un-recrystallized austenite. The present invention further stipulates a P value to the range of 1.9 to 4.0 and thus provides a ultra-high strength steel having a tensile strength of at least 950 MPa (not lower than 100 of the API standard) and excellent in low temperature toughness, HAZ toughness and field weldability in cold districts. <IMAGE>