Technical requirements for wear-resistant pump body castings

The wear-resistant pump body casting is the main part of the pumping system. As the pumping system used in mining machinery and equipment contains hard particles, during the pumping process, due to vortex centrifugation and gravity, the high-density hard particles move close to the cavity wall, thereby causing erosion and great friction damage to the inner wall of the flow-through parts. In addition, the performance of the pumping system is low or ineffective due to the influence of medium corrosivity, cavitation, electrochemical reaction and other factors. Based on the analysis of various failure modes, the selection of materials needs to be comprehensively considered, so that the parts of the pumping system have the characteristics of high hardness, wear resistance, good toughness and controllable cost, so as to stabilize the performance of the pumping system and improve its service life.

The weight of wear-resistant pump body casting is 5460 kg, and the overall dimension is 814 mm × 3 067 mm × 650 mm, with a main wall thickness of 55 mm. The structure of the pump body casting is shown in the figure. Its material brand is qt600-3a, which requires that the tensile strength of the attached cast test block is ≥ 600 MPa, the elongation is ≥ 3%, the hardness is 190 HB ~ 240 Hb, the matrix structure is mainly pearlite, and the spheroidization level of the metallographic structure is not less than grade 2, that is, the spheroidization rate is greater than 90%. Due to the poor working environment of the wear-resistant pump body casting, the wear-resistant performance of the pump body casting must be guaranteed.

Through the analysis of the working conditions of wear-resistant pump body castings, the chemical composition of the wear-resistant pump body castings is determined. Through strict production process control, the use of high-quality spheroidizing agent, spheroidizing treatment and appropriate inoculation treatment process, combined with reasonable casting process and other measures, qualified wear-resistant pump body castings with better wear resistance and longer service life are produced, which fully meet the use requirements of customers.