滚装船货物甲板无污染磨料抛射除锈

本文介绍了滚装船超高型货舱甲板涂装无机锌涂料前的钢材表面处理环保型无污染磨料抛射除锈新工艺，为滚装船货物甲板大面积涂装无机锌涂料前的钢材表面处理提供了一种较为理想的工艺方法。     

上海的物流战略

集装箱吞吐量去年为1128万TEU的上海港，是世界第三大集装箱港。     

日本预应力混凝土桥梁新技术——后期粘结的PC钢材

无粘结预应力束是由单根或多根高强钢丝、钢绞线或钢筋，沿全长涂抹防腐蚀油脂并用聚乙烯热塑套管包裹而成。无粘结束像普通钢筋一样敷设，然后浇注混凝土，待混凝土达到规定强度后，进行张拉和锚固，它省去了预埋套管、穿索和压将工艺，节省了施工设备，简化了施工工艺，     

国内外主要钢材牌号对照

<正> 世界各国钢材均有自己国家的牌号,其标准代号也不尽相同,为使各国常用钢材相互等同使用,现将造船中常用的普通结构钢与优质碳素结构钢的牌号作些介绍以供选用参考。     

如何挑选和保养铝合金轮辋

近年来，铝合金轮辋越来越深入人心．这跟它所具有的质量小、省油，抗变形能力强，车动力损失小，散热性好．造型美观的特点很有关系．但是客观地讲铝合金轮辋也具有不少缺点，因为铝合金材质本身较脆容易出现细小的裂纹，所以很难被发现，它的强度也没有钢材料离，再加上相对较高的价格，大家在选购及保养铝合金轮辋时还是需要仔细斟酌。     

Effects of cooling rates on microstructures and mechanical properties of Nb-Ti microalloyed steel

The mechanical properties and microstructure of as-cast Nb-Ti microalloyed steel at different temperatures and cooling rates are investigated in this paper. The III brittle zone (700?C900°C) is revealed. The reduction of the hot ductility is due to the film-like proeutectoid ferrite or the Nb(C, N) precipitates along the austenitic grain boundaries. In the temperature range of 850?C1 000°C, with the increase of the cooling rate, the hot ductility decreases. However, in the range of 650?C850°C, the appearance of large volume fractions of ferrite on austenite grain boundaries minimizes the effect of cooling rate on hot ductility. When the cooling rate is 10°C/s, austenite transforms more quickly to ferrite and at a lower temperature a larger amount of ferrite nucleates and precipitates in the grain, which leads to a sharper improvement in the hot ductility at 650°C.