文章介绍了离心球墨铸铁管采用电磁超声技术进行在线测厚的开发过程,包括系统原理、系统组成、系统创新点、系统关键技术等方面,开发实现了离心球墨铸铁管壁厚在线检测,为国内首创,促进了离心球墨铸铁管壁厚均匀性提高和铁耗的减少,取得了显著的经济和社会效益.

WC-CoCr coatings were prepared on 45 steel by HVOF,and the high temperature oxidation test and thermal shock test of the coating in air atmosphere were carried out.The microstructure,phase of the coating before and after oxidation test and the mass gain of the coating were examined by SEM,XRD and electro balance.The results show that the microstmcture of the coating prepared by HVOF is dense and the porosity is low.The surface of the coating after oxidation at 600 ℃ in static air generates the oxidation production of CoWO4,WO3,Cr2O3.The oxidation product can furtherly hinder the oxidation of the coating,and then,the oxidation resistance properties of the coating improve.The coating does not peel off.WC-CoCr coatings have good oxidation resistance and thermal shock performance.

The production process of Si-Mn alloying wear-resistant bainite ductile iron pipe was researched in this paper.By discussion on its chemical compositions,structure and performance and so on,it was indicated that the bainite ductile iron pipe had good formability,high hardness,excellent toughness.Its heat-treatment process was simple,and production cost was low,so the application of this kind of iron pipe would have a broad market prospect.