发动机缸体用高强度灰铸铁切削加工性能研究

Study on Machinability of High Strength Gray Cast Iron for Engine Cylinder

分别选用Ba Si/Sr Si孕育剂,经相同合金化制备了两种强度相当的发动机缸体用高强度灰铸铁试样。对比研究了两种试样的力学性能及显微组织,从所受切削力的大小以及对刀具的磨损程度评价了两种试样的切削加工性能。结果表明:具有同等强度的两种试样,其硬度基本相同;Sr Si孕育的试样其断面敏感性优于Ba Si孕育的试样;在相同切削条件下,切削Ba Si孕育的试样时,其刀具磨损较严重,刀尖部位网状裂纹较多;Sr Si孕育的试样其切削合力比Ba Si孕育的试样降低了7%。

Two kinds of high strength gray cast iron for engine cylinder with the same tensile strength were prepared in the experiment, by adding the same alloy elements but selecting two different inoculants of BaSi/SrSi. The mechanical properties and microstructure of two kinds of samples were comparatively studied, and the machinability was evaluated through the cutting force and cutting-tool wear. The results show that the two kinds of samples with the same tensile strength and approximate hardness; the section sensitivity of the sample inoculated by SrSi are better than BaSi; under the same conditions, during cutting the sample inoculated by BaSi, the cutting-tool wear is more serious, and the reticular crack of tool nose is more; 7% resultant tool force was reduced in cutting the sample inoculated by SrSi in contrast with BaSi.