Main materials of wear-resistant plate parts

Steel wear-resistant materials are basically used for large wear-resistant plate parts. At present, the wear-resistant plate materials that have been industrialized and engineered can be divided into the following categories:

(1) Wear resistant white cast iron

No matter at home and abroad, wear-resistant white cast iron has always been the mainstream of wear-resistant plate materials. In China, Japan, the United States and other large iron and steel industry countries, Cr15, Cr20 and Cr26 series of high chromium cast iron have achieved large-scale production and application. In addition, China has developed low chromium wear-resistant cast iron and medium chromium silicon wear-resistant cast iron which can directly use as cast workpiece on the basis of high chromium cast iron.

In recent ten years, improving the hardness of high chromium cast iron is the main development direction to solve the problem of wear resistance of plate parts under the condition of wear and erosion. The application practice shows that the hardness of wear-resistant white cast iron should be at least HRC60 if it wants to better meet the wear-resistant requirements, and HRC63 indicates that the wear-resistance of cast iron is improved greatly. After the refinement treatment, the section size of the high carbon ultra-high chromium hypereutectic white cast iron in this grade of wear-resistant white cast iron is mostly below 40m, and the maximum is no more than 80 The primary M7C3 phase of PM. Thanks to the carbide with high hardness and high volume ratio, the hardness of the sample after heat treatment reaches hrc63-68, and the impact toughness reaches 4.0-5.5j/cm2. Its properties are similar to those of A217 high carbon ultra-high chromium white cast iron produced in Australia,

At present, the material is mainly used for the overflow part of slurry pump. In addition, another kind of high chromium cast iron is alloyed by c-cr-w-mo. with the help of W and Mo, it can form strong carbides to improve the CR / C ratio and Cr equivalent of Cr26 high chromium cast iron, and then improve the hardness and volume fraction of M7C3 in cast iron. It shows excellent wear resistance in low angle salt water mortar erosion corrosion test.

(2) Austenitic wear-resistant manganese steel

At present, the austenitic manganese steel used in production at home and abroad is mainly Mnl3 series, and some countries such as Japan highly recommend mnl3cr2 wear-resistant steel with high wear resistance and yield strength. Austenitic manganese steel is mainly characterized by certain strength, high workability and easy work hardening. The maturity of its application can be reflected in the standardization. At present, the main industrial developed countries have national standards for austenitic manganese steel. As early as 1999, the international standard for austenitic manganese steel castings (is013251:1999) was born. In China, the relevant departments have already formulated the national standard for castings of austenitic manganese steel (GB / t5680-1998) and the national standard document for metallography of cast high manganese steel (GB / t13925-1992).

(3) Other alloy materials

In addition to wear-resistant white cast iron and austenitic manganese steel, wear-resistant plate materials mainly include wear-resistant alloy ductile iron, wear-resistant alloy steel, wear-resistant steel-based composite materials, etc. Some people use liquid quenching heat treatment to produce martensitic wear-resistant ductile iron with certain toughness and high hardness at the same time, or through liquid quenching heat treatment and alloying of Mn and other elements to produce bainite Mn martensitic wear-resistant ductile iron with good hardness and toughness at the same time. These two kinds of wear-resistant ductile iron have been applied to wear-resistant ball mill lining plate and other wear-resistant ductile iron in China Plate type parts.

The application scenario of wear-resistant alloy steel is mainly the liner of wet ball mill in metallurgical mines. In the application of high manganese steel to the lining plate of the wet ball mill of aluminum ore in the aluminum oxide plant, the obvious alkali embrittlement cracking phenomenon occurs due to the action of hot strong alkaline aluminum ore slurry, which indicates that this kind of material is not suitable for the working condition at this time. In order to solve this problem, a multi-element low-alloy martensitic cast steel liner with low chromium content has been developed. The above problems have been solved, and the application and industrial production have been successfully carried out.

In most cases, wear-resistant steel matrix composites reinforced by ceramic particles have been prepared into surface hardened surface composites. The wear of strong rolling or sliding friction, especially abrasive wear, requires a higher thickness of wear-resistant composite layer. Based on this situation, WC and other ceramic particles reinforced wear-resistant steel-based surface composite materials have been greatly developed in the application of steel rolling guide plate and chute lining plate. At present, the surface cast infiltration technology developed from plane to arc is the key and difficult point in the field of wear-resistant steel-based composite materials.