Influence of impurity element titanium on cutting performance of gray cast iron

The comparative experiment of cutting performance of gray cast iron was carried out on CA6140 lathe, and the nsdn-45 ° straight cutting tool produced by Yiquan, Taiwan was selected as the clamping tool. During the experiment, the sample shall be processed to Φ 88mm, new blades are used for each group of samples, and the diameter is Φ At 88mm, the cutting depth is 3.00mm, turning all the time. The cutting length of gray cast iron is about 600 mm. The cutting force is measured during cutting, and the measurement results are shown in table 4-9. During turning, the spindle speed of the machine tool is 180 R · min-1 and the feed rate is 0.286 mm · R-1. The shape of the blade is a diamond 80 degree blade, and the geometric parameters of the tool: the fillet diameter of the tool tip is 0.8 mm, and the thickness of the blade is 4.76 mm. After cutting gray cast iron, the tool wear morphology was observed and analyzed by JSM-5610LV scanning electron microscope.

It can be seen from the table that under the same cutting conditions, the three-dimensional cutting force and cutting resultant force of gray cast iron samples melted with low titanium pig iron are significantly lower than those of z14 cast gray cast iron. When the tensile strength is basically the same, the cutting resistance of the gray cast iron sample melted by low titanium pig iron is 4.09% lower than that of z14 cast gray cast iron. The smaller the cutting resistance of the sample in the cutting process, the smaller the tool wear during cutting.

The figure is the schematic diagram of tool wear after cutting two kinds of gray cast iron samples. In the process of cutting, the cutting tool shears the workpiece material to make it deform, the material is damaged and collapses to form iron filings, which continuously flow through the front face of the cutting tool, and the cutting tool and chip are constantly worn due to mutual friction. It can be seen from the figure that the coating of the cutting tool will be impacted by heating for a long time, causing the coating to fall off, and the coating will fall off, exposing the cemented carbide matrix of the cutting tool. There is little difference in the wear area of the tool in the two photos, but the damage degree of the rake face is quite different. It can be seen from photo (a) that the wear of the tool surface is uneven and some areas are seriously worn. In photo (b), the overall wear of the tool is more serious, the tool surface is seriously damaged, and the roughness of the wear area is large.