タングステン・カーバイドロールの腐食摩耗に及ぼす冷却水質の影響

抄録

Tungsten Carbide Cemented Rolls are widely used in hot-steel-products rolling because of good wear resistance. At the early period, small diameter ring rolls with tungsten carbide mounted on steel parts were used in finishing cantilever blocks of wire rod mills. Recently, medium diameter ring rolls and solid rolls with tungsten carbide have been used in modern intermediate stands of rod mills and stretch reducing stands of tube mills. Moreover, they have started to be applied to finishing stands in stainless section mills because of good galling resistance. But the tungsten carbide rolls is very expensive compared with the conventional cast iron rolls. To apply tungsten carbide rolls instead of cast iron rolls economically, it is necessary to get about five to ten times roll life of cast rolls. In this report, the corrosive characteristic of tungsten carbide alloy in high temperature water, which is one of main reasons for roll wear, is investigated. It was found that the optimization of the pH and calcium concentration of cooling water is effective to suppress corrosion of rolls. This effect was assured in the real production of three roll type stretch reducing stands of the tube mill in Kashima Steel Works.