Superplastic dual-phase stainless steels having a small deformation resistance and excellent elongation properties

A superplastic dual-phase stainless steel having a low deformation resistance and an excellent elongation, comprising C:

• not more than 0.05 wt %, Si:
• not more than 1.5 wt %, Mn:
• not more than 3.0 wt %, Cr:
• 17.0-26.0 wt %, Ni:
• 3.0-10.0 wt %, Mo:
• 0.1-2.0 wt %, N:
• 0.08-0.20 wt %, S:
• not more than 0.002 wt %, B:
• 0.0005-0.01 wt %, Cu:
• 0.1-2.0 wt % and the remainder being Fe and inevitable impurities, wherein contents of Cr, Ni, Mo, Si, C, Mn, Cu, and N satisfy a difference Cr.sub.eq -Ni.sub.eq between Cr.sub.eq defined by the following equation (1) and Ni.sub.eq defined by the following equation (2) of 12.0-17.0.
• Cr.sub.eq =Cr+Mo+0.5Si (1)
• Ni.sub.eq =Ni+30C+0.5Mn+0.5Cu+20N (2).
• 3.