The Research Of The Gray Cast Iron Used In Cylinder With Inexpensive And Good Machinability

In order to realize the sustainable development of the auto industry, peopleshould pay more attention to the environment pollution and energy consumption thanthe engine’s power. So the engine cylinder with good heat dissipation, strongtoughness, corrosion resistance, abrasion resistance, machinability and economy isrequired. However, the strength and processing performance of gray cast iron which isproducted in China are poor at present. It’s necessary to develop the engine blockmaterial with low cost, high strength and good machinability to adapt to the impact ofthe integration of the world economy.The mechanical and cutting performance properties of the gray cast iron withvarious inoculants (75SiFe, SrSi，BaSi) and additive elements, including the mixtureof (RE, Cr, Mn, Si, Fe) and Cu were studied in this paper. The mechanical propertiesare texted by the tensile strength, brinell hardness and microhardness, and theprocessing performance is evaluated by cutting force. The material is hardly to cutwith a high cutting force, so the processing performance is poor, while the processingperformance is good when using a low cutting force. In addition, the influence ofchainging and reloading of the cutting tool on the cutting force during the cuttingprocess is investigated.The results show that the section sensitivity of the gray cast iron with75SiFeand the mixture is smaller than that of the gray cast iron with75SiFe and Cu. Thetensile strength of the gray cast iron with75SiFe and the mixture is6.5%less than thatof the gray cast iron with75SiFe and Cu, while the main cutting force of the gray castiron with75SiFe and the mixture is3.7%-7.7%(cutting depth1-1.5mm) less thanthat of the gray cast iron with75SiFe and Cu. The tensile strength of the gray cast ironwith the mixture and various inoculants is almost the same, while the cuttingperformance property of the gray cast iron with SrSi is best. The tensile strength,brinell hardness and the micro–hardness of the two irons are the same, but the main cutting forces of the gray cast iron with75SiFe and the mixture is13%-20.2%(cuttingdepth1.5-2.0mm) less than that of the gray cast iron with75SiFe and Cu.