The depositability of high strength steel in hot dip galvanizing line has always been the focus of research.High-strength steel tends to contain many elements such as Si and Mn, which are easy to accumulate on the surface of the substrate, resulting in multiple surface defects when hot-dip galvanizing.Through the adjustment of chemical composition, especially the addition of Mo elements, Japan has realized the commercial production of double-phase alloy hot-dip galvanizing. Low-si content dual-phase steels have been produced in the traditional hot-dip galvanizing production line, for example, DP600:The yield strength and tensile strength reached 320MPa and 630MPa, respectively, with a total elongation of 26% and n value of 0.18126]. High-strength steel with high Si content is still the main direction of current research..., which needs to be studied on the atmosphere in the annealing furnace and the control of the dew point in the furnace. The pretreatment of the substrate can also solve the enrichment problem of Si and other elements.Based on the alloy hot-dip galvanizing biphase steel, kawasaki iron and steel co., LTD has developed the low carbon equivalent alloy hot-dip galvanizing steel with good spot weldability
TRIP steel (i.e., phase-change induced plastic steel) has excellent molding, strength and impact resistance, and is auto weight reduction and energy saving Ideal for steel.However, the conventional TRIP steel with high Si content is not suitable for production in the existing hot dip galvanizing line, which is also because the enrichment of Si can easily lead to leakage plating defects in the coating.Although the chemical composition of the strip surface can be changed by controlling the dew point in the annealing furnace to improve the coating quality, the leakage area cannot be completely eliminatedIn addition, the isothermal transformation temperatures by dry is limited by zinc pot temperature is too high, so can't get enough of residual austenite, . The study found that can replace Si of TRIP steel with A1 type and traditional CMnSi TRIP steel performance, but also. It will be in the existing hot plating process, has the very good mirror can be [20, but as a result of A1 elements added, to the steelmaking and hot rolling technology has brought many problems, how to solve these problems is one of the focus in the study of TRIP steel galvanized,X. Vanden Eynde et al. A130 proposed a new process of pre-heating and forming homogeneous oxide layer of si-containing TRIP steel before conducting self-reduction. In laboratory studies, it was found that the hot-dip galvanizing TRIP steel produced by this process had good plating performance.