Cast iron working under abrasive wear conditions should have high and uniform hardness. White cast iron belongs to this type of cast iron. However, because white cast iron is brittle and cannot withstand impact loads, chilling is often used in production to obtain chilled cast iron, that is, the wear-resistant surface of metal castings is used, and sand casting is used for other parts. At the same time, adjust the chemical composition of the molten iron and adopt high-carbon and low-silicon, which can not only ensure the depth of the white layer, but also ensure that the core is still gray cast iron structure. The chilling method is used to manufacture wear-resistant cast iron, which has been widely used in the casting production of rolls and wheels.
Wear-resistant castings that work under lubricated conditions require a hard structure to be firmly embedded on a soft matrix. When the soft copy body is worn out, grooves are formed to maintain the oil film. Pearlitic gray cast iron can basically meet this requirement. In its structure, ferrite is a soft matrix and cementite is a hard component. At the same time, graphite flakes also play a role in oil storage and lubrication. High-phosphorus cast iron has high wear resistance because it contains high-hardness phosphorus eutectic. On this basis, if alloying elements such as Cr, Mo, W, Cu are added, the microstructure and properties can be improved, and the strength and toughness of the matrix can be improved, so that the wear resistance of cast iron can be greatly improved.
In addition to high-phosphorus cast iron, vanadium-titanium wear-resistant cast iron, chromium-molybdenum-copper wear-resistant cast iron and boron wear-resistant cast iron also have excellent wear resistance.