| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a low yield ratio type high strength steel sheet good in shape freezability, securing the objective martensitic structure while being reduced in the addition amount of alloys increasing the production cost, good in the adhesiveness galvanizing and also applicable to a high corrosion resistant surface treated steel sheet. SOLUTION: In this high strength steel sheet excellent in shape freezability and adhesion for plating, Ni is contained to a high concentration of 0.03 to 2.0%, the contents of Si and Al forming nitrides are respectively controlled to <=0.2% and <=0.3%, the cooling rate in an annealing stage is controlled, if required, Ca, Na, Mg or the like for controlling the formation of iron nitrides are added, and the abundance ratio of a martensitic phase in the metallic structure is controlled to 3 to 30%.</p> |
