WC roll rings are subjected to high temperature, rolling stress, thermal corrosion and impact load during the hot rolling process. Compared with WC roll rings produced abroad, the purity of the raw materials used to manufacture roll rings in my country, There is still a certain gap in the processing technology and performance indicators of the roll ring. The wear resistance of the roll during use is poor and the roll ring is easy to break. On the basis of ordinary carbide roller ring materials, the lubrication and wear-resistant gradient material LubricationGradientMaterial (LGM for short) was used to develop the gradient material LGM roller ring.
This technology adds sulfur and oxygen to ordinary cemented carbide materials to form stable gradient metal oxides and metal sulfides (Co3O4 and CoS respectively) on the surface of the metal substrate. Co3O4 and CoS have good lubrication and wear resistance properties. Industrial tests of LGM roll rings show that the sulfides and oxides in gradient materials can reduce the friction coefficient during rolling, significantly improve the lubrication performance of the roll ring under high temperature and large rolling force conditions, and reduce the risk of transverse cracks. Generated, the service life of the roller ring is 1.5 times that of ordinary carbide roller rings, and it can reduce the amount of grinding and the number of roller changes, which has significant economic benefits.
Using CIC technology, we developed H6T, the cemented carbide roller ring with the smallest binder phase in the world. Its binder phase content is only 6, but its hardness and wear resistance are significantly higher than ordinary grades of alloys, especially the wear resistance. The grinding performance is improved by 50%; when used on the finished product frame and the finished product front frame, the roll life is 2 times that of ordinary carbide grades; it better solves the problem of changing the rolls of the finished product frame and the finished product front frame together. It can significantly reduce the number of groove changes and roll changes, thereby improving the effective operation rate of the rolling mill.
CIC composite carbide roller rings have been used in wire rod mills (intermediate rolling or pre-finishing rolling), bar rolling mills (intermediate rolling, finishing rolling), small steel rolling mills (square steel, hexagonal brazed steel, Flat steel and angle steel, etc.) and three-roll mill systems (such as KOCK wire bars, seamless steel pipe tension reducer). When the composite carbide roller ring is used in the finishing rolling stand of a high-speed wire rod rolling mill or a small bar rolling mill, the rolling volume of its single groove per groove is 10 times that of ordinary cast iron rolls, and the grinding volume per time is only that of cast iron. 1/3 to 1/2 of the roller. Therefore, compared with the traditional cast iron roller, the total rolling volume of the composite roller is 20 to 30 times that of the ordinary roller. When used in seamless steel pipe 3-roller tension reducer frames and pipe jacking frames, compared with traditional cast iron tension reducer rollers, the single groove rolling capacity of composite rollers is ordinary when rolling larger diameter steel pipes. 20 times that of cast iron rollers. When rolling smaller-diameter steel pipes, the single-groove rolling volume of composite rollers is 40 times that of ordinary cast iron rollers, and the finished product quality and dimensional accuracy of steel pipes are significantly improved.
In order to solve the problems existing in alloy tool steel and carbide roll materials used in the production of threaded steel wires, carbide GW30, which is between alloy tool steel and carbide, was developed. After forging, machining and heat treatment, the "bridging" phenomenon of carbides in the alloy is weakened, and the material's bending strength and impact toughness reach 2672MPa and 18.0J/cm2 respectively, which can prevent early brittle failure of the roll. At the same time, the wear resistance of the hard phase in the cemented carbide was fully utilized. Under the condition of maintaining the strength and toughness of the roll, the surface of the roll was treated with boronization, so that the boronization layer was firmly combined with the steel matrix. The microstructure and properties tend to be consistent, further improving the wear resistance of the alloy. Industrial test results show that the service life of the roll is more than ten times that of alloy tool steel, and the economic benefits are significant.