POSCO Holdings Inc.
Zn alloy plated steel sheet having excellent phosphatability and spot weldability and method for manufacturing same

Abstract:

A Zn alloy plated steel sheet having excellent phosphatability and spot weldability and a method for manufacturing the same are provided. In the Zn alloy plated steel sheet including a base steel sheet and a Zn alloy plating layer, the Zn alloy plating layer includes, by wt %, Al: 0.5-2.8%, Mg: 0.5-2.8%, and a remainder of Zn and inevitable impurities, and a cross-sectional structure of the Zn alloy plating layer includes, by area percentage, more than 50% of a Zn single phase structure and less than 50% of a Zn--Al--Mg-based intermetallic compound. A surface structure of the Zn alloy plating layer includes, by area percentage, 40% or less of a Zn single phase structure and 60% or more of a Zn--Al--Mg-based intermetallic compound.