The Research Of Domestic Manufacture Of Cored Hard Alloy Wire For Harding Rollers

Along with the market economy is in motion in China and in therequirements of enterprise expansion, it has become common view to reducemanufacturing costs and consumption and to increase economy benefits.Build-up welding rolls (hot roll, supporting roll, top/bottom pinch rolls,wrapper roll, guide roll, measuring roll, etc.) are key facilities for steel rollingmanufacture. Work efficiency of the rolling mills, quality and output of therolling products, as well as consumption of the rolls will be affected directly byquality of the cladding. And quality of the rolls will be affected mostly by thebuild-up welding material. Therefore, the article is to optimize the preferredbuild-up welding material for field on the basis of mature technology both athome and abroad also in accordance with practical needs and field conditions ofWelding Plant of CFHI. The research not only has the definite theoreticalsignificance but also has the important practical significance for homemade flux-cored wire and reduction in production costs.This article states status of development status both at home and abroad ofbuild-up hard alloy flux-cored wire for pinch roll or wrapper roll and newprogress of build-up welding procedure. The contrast tests were done on theexisting three type iron base hard alloy flux-cored wire, 258-SA+flux RECORD-SA (Belgium), DIAMOND324+flux SSD-â…¡(Shanghai, China), LBS422+fluxSSD-â…¡(Heilongjiang, China), of China first heavy industries at present. Besides,the study and theoretical analysis were done on post weld heat treatment system,chemical composition of cladding, dilution law, microscopic structure, hardnessand macroscopic shape. From the factors, such as manufacturability and price, tooptimize a type hard alloy flux-cored build-up welding material this would be the most economical and would satisfy the procedure requirements.The welding quality of build-up welding includes internal quality andexternal quality. Internal quality mainly depends on whether or not there iswelding defects, such as gas porosity, slag inclusion, etc. External quality mainlydepends on bead formation, bead overlap and bead plainness, etc. Throughcontrast analysis, the results showed that the manufacturability of wire 258-SA+flux RECORD-SA (Belgium) is better than that of wire DIAMOND324+fluxSSD-â…¡(homemade) and LBS422+flux SSD-â…¡(homemade) either. Themanufacturability of wire DIAMOND324+flux SSD-â…¡(homemade) andLBS422+flux SSD-â…¡(homemade) is well matched. The uniformity of chemicalcomposition of three type wires satisfies the operating requirements. The indexes,such as hardness and resistance to wear etc, are well matched. The above-mentioned three type wires were used for hard alloy build-up welding rolls ofmany steel corporations, such as Baosteel, Ansteel, Bensteel, Wusteel, etc. Anddepend on the feedback information of service condition, the service life ofcladding of these wires (wire 258-SA, wire DIAMOND324, wire LBS422) werewell matched, none of them showed excellent characteristics. But, the price ofis far lower than the imported, so the imported cored hard alloy wire can bereplaced by the domestic.