| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a steel plate having excellent chemical convertibility and corrosion resistance used for automobile inner and outer plates and underbody structure members.SOLUTION: An automobile steel plate having excellent chemical convertibility and corrosion resistance comprises, by mass%, C: 0.0005-0.3%, Si: 0.01-3%, Mn: 0.01-5%, P: 0.001-0.1%, S: 0.01% or less, Al: 0.005-2%, N: 0.01% or less, Cu: less than 0.05, Sn: 0.005-0.5%, with the balance being Fe and unavoidable impurities, and has iron surface roughness (average roughness Ra) of 0.5-2μm.</p> |
