Machining the refractories and constructing the lining of equipment for the vacuum treatment of steel

Conclusions

A section has been organized at the Magnezit Plant for the machining and checkout assembly of MKhVP and MKhV refractories for VTS equipment. The section is equipped with a column- and-knee type milling machine, surface grinders, and stands for the checkout assembly of the bottom and roof of the vacuum chamber and the hood cover.

The masonry elements are shaped and a high quality of masonry work for the lining of VTS equipment is achieved by cutting and grinding the refractory bricks with diamond tools during a checkout assembly of the masonry. A total of 30–50% of the bricks used in the lining are machined in this manner.

The tools are AOSK-type diamond disk saws for cutting and a face-plate built up of diamond-bearing bars for grinding the refractories. The bonding substances of the tools is a hard alloy (M50). The granularity and concentration of the diamonds are not significant factors in the machining productivity and the finish of the machined surface. The refractories are machined without a coolant feed in the cutting zone.

An investigation was carried out of the principal cutting parameters for magnesia refractories. The conditions for dry-machining refractories with an AOSK-type diamond disk saw bonded with M50 are as follows (horizontal feed of the work to the tool): cutting speed, 46–50 m/sec; feed, 0.8 m/min; depth of cutting, 60 mm; productivity, 480 cm²/min; and diamond consumption, 10–12 carat/m².