On the basis of laboratory test and research,galvannealed dual-phase steel DP980-GA was successfully developed relying on industrial continuous galvanizing line(CGL).The results show that microstructure of the steel substrate is composed of ferrite,martensite and a small amount of bainite.The phase structure of the coating is composed of thin Γ layer with 0.6 μm thickness near the substrate,principal phase δ and a small amount of ζ phase,where the Fe content in the coating is around 10.5％.The mechanical properties of the DP980-GA steel product show low yield ratio(0.624),good elongation and hole expansion ratio.The industrial mass produced products were applied to parts such as A pillar inner,of which the process capacity of yield strength,tensile strength and elongation is controlled stably.
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