High strength wear-resistant castables are composed of the following components:
A. hard aggregate B. micronized filler C. binding agent D. wear-resistant agent
Among them, hard aggregate constitutes the skeleton part of ceramic wear-resistant material, micronized powder fills the gaps, and the overall dense structure is formed through the binding agent to form a wear-resistant liner with high strength to achieve the purpose of wear and corrosion resistance. Wear is a complex process in which solids, liquids, gases and mixtures of abrasive particles, etc. and the surface of an object produce relative motion and cause the object to lose continuously.
According to the friction surface of the wear process and destruction mechanism characteristics, the wear is divided into abrasive wear, adhesive wear, corrosive wear. Frequently encountered wear is usually a combination of several kinds of wear, high temperature wear is actually a combination of adhesive wear and abrasive wear. High-strength wear-resistant castables according to the wear mechanism of the material, to improve the wear-resistant performance of the liner, should start from the following aspects:
First, the hardness of liner body material
Generally speaking, only the hardness of the liner wear-resistant material is higher than the hardness of the abrasive material, in order to improve the wear resistance of the liner material. However, it is not the higher the hardness the better, only the material hardness and fracture toughness is in the best fit, the wear resistance performance is optimal. At high temperatures, not only requires good high temperature red hardness, and the abrasive media reactivity should be small.
Second, the liner and matrix material matching matrix without strain
Lining body for load work, the basic should have enough hardness and yield strength, in order to support the lining body does not deform, does not produce large stress caused by separation. At the same time, the liner and the matrix material in the coefficient of rigidity and expansion, the modulus of elasticity should be matched, so as not to cause non-work damage, and the liner and the matrix material should be good, only the formation of the maximum chemical affinity without brittle interfacial phases, in order to give full play to the role of wear-resistant liner.
Third, the combination strength between particles of lining material should be high.
High strength wear-resistant castables should have high bonding strength between particles. Substrate and hard aggregate firmly stick together, without spalling, in order to give full play to the high wear-resistant performance of the hard phase. In actual use, most of the wear is due to the combined phase is damaged by abrasive particles, hard aggregate off, can not give full play to the role, so improve the hardness and strength of the combined phase is crucial.
Fourth, the liner material corrosion-resistant wear
Wear-resistant lining in corrosive media wear resistance also depends on the wear-resistant materials in the chemical medium of corrosion resistance, can not react with corrosive media, otherwise the wear-resistant lining materials greatly reduced, lining materials and corrosive substances in the chemical composition of changes in the structure of the lining body is destroyed, thus losing wear resistance.
Fifth, construction methods and maintenance
Wear-resistant lining body has a specific construction method and maintenance requirements, the Engineering Department in strict accordance with the initial development of the construction program implementation, if you change the construction method or lack of necessary maintenance, the strength and bonding properties will not be the best, it is difficult to meet the design requirements.