High-silicon heat-resistant vermicular graphite cast iron with thermal fatigue resistance and high performance and preparation method thereof

Abstract

The invention provides high-silicon heat-resistant vermicular graphite cast iron with thermal fatigue resistance and high performance and a preparation method of thereof, and belongs to the technicalfield of alloy preparation. The vermicular graphite cast iron comprises the following components of, in percent by mass, 2.50%-3.50% of C, 4.50%-5.50% of Si, less than or equal to 0.30% of Mn, less than or equal to 0.050% of P, less than or equal to 0.020% of S, 0.60%-0.90% of Mo, 0.50%-0.9% of Ni, 0.40%-0.80% of Cr, 0.30%-0.60% of V, 0.20%-0.40% of Nb, less than or equal to 0.20% of Cu, 0.10%-0.20% of Ti, 0.010%-0.020% of Mg, less than or equal to 0.05% of RE, less than or equal to 0.05% of Al, and the balance iron. According to the high-silicon heat-resistant vermicular graphite cast iron with the thermal fatigue resistance and the high performance, various alloy elements are optimally compounded and matched for use, so that the vermicular graphite cast iron has excellent thermal fatigueresistance and high-temperature strength and has good dimensional stability and good heat-conducting capacity at high temperature, and the vermicular graphite cast iron can be used for a CNG vehicleengine turbocharger turbine shell and exhaust pipe. Meanwhile, the vermicular graphite cast iron meeting the requirement of being applied to the CNG vehicle engine is obtained through the preparationmethod of the vermicular graphite cast iron.

Description

technical field [0001] The invention belongs to the technical field of alloy preparation, and in particular relates to a high-silicon heat-resistant vermicular graphite cast iron with high thermal fatigue resistance and a preparation method thereof. Background technique [0002] Energy crisis and environmental pollution have become one of the urgent problems we face to be solved. In terms of urban air pollution, diesel engines and gasoline internal combustion engines are the main sources of air pollution. Therefore, in recent years, natural gas as a new type of energy has received widespread attention at home and abroad. The development of natural gas resources and vehicle technology research are developing rapidly as new frontiers. Natural gas special engines can be compared with equivalent gasoline engines and diesel engines through good control. With lower emissions, it is beneficial to solve the increasingly serious air pollution problem; at the same time, compared with...

AI Technical Summary

Problems solved by technology

This kind of turbocharger turbine shell and exhaust pipe materials made of existing silicon-molybdenum ductile iron, molybdenum-nickel vermicular iron, high-nickel ductile iron and even heat-resistant steel have passed many engine test bench durability tests and urban bus In the vehicle loading test, the turbine shell and the exhaust pipe all have different degrees of thermal fatigue cracking, which affects the performance of the engine and even causes functional failure.

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