热冲压镀锌钢板镀层组织分析与应用  

THE COATING STRUCTURE AND APPLIICATION RESEARCH OF HOT STAMPING GALVANIZED SHEET

作　　者：魏元生 熊自柳 宋帅 董伊康 Wei Yuansheng;Xiong Ziliu;Song Shuai;Dong Yikang(HBIS Materials Technology Research Institute,Shijiazhuang 050023,Hebei)

机构地区：[1]河钢材料技术研究院,河北石家庄050023

出　　处：《河北冶金》2024年第6期34-39,共6页Hebei Metallurgy

摘　　要：镀锌热成形钢是继铝硅镀层后一种新的镀层热成形钢,具有良好的耐腐蚀及阴极保护性能、防止钢板加热时表面高温氧化起皮和脱碳、优良的外观和冲压性能、较好的焊接和涂镀性能等优点。锌基镀层化学成分为99%Zn、<1%Al及其他杂质,当镀层温度<600℃时,Al与基体中的Fe在镀层与铁基体界面处生成约1μm厚的Fe 2Al 5抑制层,阻止基体中的Fe原子向镀层中扩散;镀层温度800℃时,镀层中的Al元素基本都迁移至镀层表面,形成连续的Al 2O 3薄膜阻碍Zn的蒸发。镀层温度增加≥700℃后,抑制层破坏,大量Fe元素扩散进入镀层形成Al、Fe化合物相,镀层体密度变化增厚。镀锌热成形钢的奥氏体化加热温度、保温时间、入模成形温度对零件的耐腐蚀性、镀层液相脆性LME防控有直接影响,最佳的工艺参数为加热温度880℃、加热时间360 s、入模成形温度≤700℃。镀锌热成形钢板的焊接及涂装性能良好,在汽车车身安全结构件有很大的应用前景。Hot-formed galvanized steel is a new kind of hot-formed coated steel after aluminium-silicon coating.It has good corrosion resistance and cathodic protection performance,prevents the surface from scaling and decarburization at high temperature when heating the steel plate,has excellent appearance and stamping performance,and good welding and coating performance.The chemical composition of the zinc-based coating is 99%of Zn,<1%Al and other impurities.When the coating temperature is less than 600℃,the Al and Fe in the substrate forms a Fe 2Al 5 inhibition layer of about 1 um thickness at the interface between the coating and the iron substrate,preventing the diffusion of Fe atoms in the substrate into the coating;When the coating temperature is 800℃,the Al elements in the coating basically migrate to the coating surface,forming a continuous Al 2O 3 film to prevent the evaporation of Zn.When the coating temperature increases more than 700℃,the inhibition layer is destroyed,a large number of Fe elements diffuse into the coating to form Al and Fe compound phases,and the coating thickness increases with the change of coating bulk density.The austenitizing heating temperature,holding time and injection molding temperature of galvanized hot-formed steel have a direct impact on the corrosion resistance of parts and LME prevention and control of liquid phase brittleness of coating.The best process parameters are which with heating temperature 880℃,heating time 360 s,injection molding temperature less than 700℃.The galvanized hot-formed steel sheet has good welding and coating properties,and has great application prospects in the safety structural parts of automobile body.

关 键 词：热冲压 镀锌层 抑制层 扩散 入模温度 液相金属脆性 

分 类 号：TG174.4[金属学及工艺—金属表面处理]