HOT-PRESSED MEMBER AND METHOD FOR PRODUCING THE SAME

摘要

Disclosed is a hot-pressed member which comprises: a steel sheet that constitutes the member and that has a surface layer in which an Ni diffusion region is present; an intermetallic-compound layer formed on the Ni diffusion region, the intermetallic-compound layer corresponding to the γ phase present in a phase equilibrium diagram of a Zn-Ni alloy; and a ZnO layer formed on the intermetallic-compound layer. The hot-pressed member has a spontaneous potential, when immersed in 0.5-M aqueous NaCl solution saturated with air and having a temperature of 25±5ºC, of -600 to -360 mV relative to the standard hydrogen electrode. This hot-pressed member can be produced without generating any scale. The member has excellent adhesion to coatings and has excellent corrosion resistance after coating. The member can be inhibited from corroding and thereby suffering hydrogen penetration into the steel.