| 摘要 |
<p>PURPOSE: A high-strength cold rolled steel strip with excellent workability and a manufacturing method thereof are provided to obtain high-strength TRIP(Transformation Induced Plasticity) with a high tensile strength of 100kgf/mm^2 or greater, a yield ratio of 0.7 or less, and a strain hardening coefficient of 0.4 or greater. CONSTITUTION: High-strength steel comprises carbon of 0.05-0.2wt.%, silicon of 0.3-0.7wt.%, manganese of 4-7wt.%, phosphorus of 0.03wt.% or less, sulfur of 0.005wt.% or less, boron of 0.0015-0.002wt.%, molybdenum of 0.02-0.05wt.%, aluminum of 0.05-0.15%, and Fe and inevitable impurities of the remaining amount. The microstructure of the high-strength steel comprises bainite of 5-20vol.%, residual austenite of 5-15vol.%, and ferrite of the remaining amount. [Reference numerals] (AA) Air cooling; (BB) Furnace cooling; (CC) Kind of alloy</p> |
