HOT-ROLLED STEEL SHEET HAVING EXCELLENT WELDABILITY AND MEHTOD FOR MANUFACTURING THEREOF

摘要

The present invention provides a high strength hot-rolled steel sheet having excellent weldability in comparison with a conventional hot-rolled steel sheet by maintaining high control and yield ratio for microstructures and a method for manufacturing the same. According to the present invention, a high strength hot-rolled steel sheet having excellent weldability, a yield ratio between 0.85 and 0.95, and improved soundness of a weld zone in welding can be obtained as steel components and hot-rolled structures are optimized. [Reference numerals] (AA) Equation; (BB) Comparative example; (CC) Example; (DD) Yield ratio(YR = YS/TS)