Research on Metal wear-resistant Materials (I)
Metal wear-resistant materials have both plastic materials and brittle hard materials, which are widely used as follows.
(1) Austenitic wear-resistant manganese steel Austenitic manganese steel is known for its high toughness and easy hardening. The austenitic manganese steel produced and applied inside and outside is still dominated by Mnl3 series, and its chemical composition is: =1.0% ~ 1.4%, =11% ~ 14%. After 1000 ~ 1050% water toughening treatment, a single austenitic structure can be obtained. So far, austenitic manganese steel is still mainly used under large impact load abrasive wear conditions (such as rolled mortar wall and broken wall of cone crusher, lining plate of rotary crusher, lining plate of large and medium-sized crusher, hammer crusher hammer head, and lining plate of large and medium-sized wet mine ball mill). Japan and other countries prefer Mnl3Cr2 wear-resistant steel with higher yield strength and wear resistance. In the 1950s and 1960s, high manganese steel was almost used as a universal wear-resistant material, but in production practice, it was found that only under the condition of large impact, high stress and hard abrasive, high manganese steel was wear-resistant, and its yield strength was low and easy to deformation.
The technical progress of austenitic manganese steel is mainly manifested in strict control of the content of Si and P which affect the performance in the production process, especially the restriction of the content of P; In addition, in order to reduce the slag inclusion, columnar crystal and grain coarseness, V, NI, RE and other trace elements are often added to high manganese steel. Mnl7(Mnl8) and Mn25, known as ultra-high manganese steel, are conducive to solving the problem that carbides are easy to appear in the interior of thick and large section manganese steel after liquid toughness treatment and reducing the toughness. They are also conducive to solving the problem that manganese steel may be brittle when used at low temperature. However, the wear resistance and cost performance of ultra-high manganese steel under abrasive wear conditions under large impact loads, the selection of Mn, C and Mn/C related to the lack of /6, especially the low life under low stress wear and other key issues need to be further studied, and the practice verification of wide application under different working conditions.
(2) The development of wear-resistant chromium white cast iron abroad is divided into three stages: ordinary white cast iron, nickel hard cast iron and high chromium white cast iron. Chromium white cast iron is still the mainstream of wear-resistant cast iron at home and abroad. Crl5, Cr20, Cr26 series of high chromium wear-resistant cast iron are mass-produced and applied in America, Japan and our country. Wear-resisting cast iron of medium chromium silicon and wear-resisting cast iron of low chromium suitable for casting application are studied in our country based on high chromium cast iron, which has been mass-produced and industrial applications.
The microstructure of high chromium cast iron after solidification is (Fe, Cr) C-type carbide and phase. When the matrix is all martensite, the wear resistance of this alloy is the best. If there is residual austenite in the matrix, heat treatment is usually required. The stability of carbide in low chromium alloy white cast iron is better than that in ordinary white El cast iron. In the study of chromium white cast iron, it is often considered that the harder the more wear resistant. In fact, the blind pursuit of hardness can not necessarily achieve the ideal effect, but will greatly increase the cost, resulting in waste. Tests have shown that high chromium cast iron in close to 90. When Angle erosion wear, its wear resistance is worse than that of 20 steel.
