A new processing method for producing hot dip galvanized steel is designed and tested, in which pickling is skipped. Hot-rolled low carbon steel sheets are roiled with oxide scale in an experimental mill at room tempe...A new processing method for producing hot dip galvanized steel is designed and tested, in which pickling is skipped. Hot-rolled low carbon steel sheets are roiled with oxide scale in an experimental mill at room temperature, prior to annealing under a 20% hydrogen reducing atmosphere and galvanizing on a hot-dip galvanizing simulator. Micro-cracks formed in the oxide scale during cold rolling roughen the steel surface and enlarge the specific surface. Through-thickness cracks provide transport channels for hydrogen, and hence the reduction of oxide scale is en- hanced. When the sheet is dipped in the zinc bath, cracks are submerged by liquated zinc and the defects are not dis- tinct after hot-dip galvanizing. The overlay coating occludes with rough surface of the sheet, whereby a superior coat- ing adherence is realized.展开更多
文摘所有的酸洗过程都是在1000级净化室和净化室内100级层流超净工作台进行的.超纯水是由Millipore RO和Milli-Q Element超纯水系统制备.3种纯度的硝酸选用Merck公司试剂纯硝酸、Fisher公司"TraceMetal"级和"Optima"级超纯硝酸.各种与样品直接接触的容器及相关工具、耗材主要选用Nalgene低密度聚乙烯和特氟隆材料制成的产品.酸洗程序是在四周时间内把样品瓶等依次浸泡在四遍不同浓度和纯度逐渐增加的硝酸溶液里进行清洗.除了第一遍酸洗是在室温下进行的以外,后三遍酸洗都是用加热板加热使硝酸溶液表面温度保持在45℃左右.用Finnigan MAT Element电感耦合等离子体质谱仪(ICP-MS)对该方法酸洗的样品瓶进行了空白检验,结果表明:所有测量的重金属元素的浓度都低于检测限.该方法对促进我国极地雪冰重金属研究具有重要意义,也可应用到其它环境介质中超痕量重金属分析.
基金Item Sponsored by National Science and Technology Pillar Program of China(2011BAE13B04)
文摘A new processing method for producing hot dip galvanized steel is designed and tested, in which pickling is skipped. Hot-rolled low carbon steel sheets are roiled with oxide scale in an experimental mill at room temperature, prior to annealing under a 20% hydrogen reducing atmosphere and galvanizing on a hot-dip galvanizing simulator. Micro-cracks formed in the oxide scale during cold rolling roughen the steel surface and enlarge the specific surface. Through-thickness cracks provide transport channels for hydrogen, and hence the reduction of oxide scale is en- hanced. When the sheet is dipped in the zinc bath, cracks are submerged by liquated zinc and the defects are not dis- tinct after hot-dip galvanizing. The overlay coating occludes with rough surface of the sheet, whereby a superior coat- ing adherence is realized.
