Study On Processing Performance Of Gray Cast Iron Of Engine Cylinder Block

Due to the shock absorption, abrasion resistance and good casting performance,gray cast iron is still used widely. At present, the selection of materials of large trucksand tractor engine block is still given priority to gray cast iron. The tendency of high-strength gray cast iron is to achieve the unity of the mechanical properties, the castingperformance and machining performance.In the present paper, the calibration device and calibration method of the stressresponse system has carried on the reform and innovation. Then a homogeneousmaterial is used as the cutting object.On the situation while the same cutting parameteris applied and tool wear can be ignored, the influence on the main cutting force by theresetting of mechanically clamped tool and the remounting of whole mechanicallyclamping tool device is examined.On this basis, the effect of Cu, Cr, the multi-alloy additive, impurity element Ti,and the type of inoculation treatment were studied. The mechanical property andmicrostructure, combined with cutting force and the wear morphology of tool, havebeen analysed systematically in the experiment.The result indicates that: in the determination of the turning force, three-axiscalibration device has the capable of simple, rapid and accurate calibration in the stressresponse system. In the testing condition, the change of cutting force caused by bladeresetting and replacing is less than2%, but that caused by the remounting of whole toolclamping device is as much as11%. When the cutting force is used to evaluate themachinability of materials, mechanically clamped tool should be used. The blade shouldbe replaceable. But the tool holder should be mounted once for all.The alloying elements Cu, Cr compound was added to improve the mechanicalproperties and machinability of gray cast iron, which improved the pearlite structure andthe hardness of uniformity. The tensile strength of gray cast iron HT300was obtained by the multi-alloy additives. The tool wear size and cutting force of that was smallerthan the gray iron alloyed by copper. Multi-alloy additive alloying treatment couldinstead of copper in terms of mechanical properties and machinability. Gray cast ironwith different titanium content were prepared by different raw material preparation. Incase of two sets of sample equivalent mechanical properties, low-titanium pig ironcasting specimens had smaller cutting force and tool wear size in the cutting process.By four inoculant inoculation, the results proved that low-alloyed with theappropriate inoculant effective bred for high-performance gray cast iron HT350. Theresults showed that the gray iron underwent the compound inoculation containing80wt.%SiSr and20wt.%75FeSi had smaller graphite morphology, higher hardness,and lower cutting resistance than those inoculated by a single inoculant. Under the sametensile strength, the cutting force of BaSi is significantly higher than SrSi.