Metallurgical Knowledge
The problem of white corundum in smelting

2016-11-30 hit:

White corundum has the characteristics of white color, high hardness, low toughness, high purity, excellent self sharpening, strong grinding force, small heat, high efficiency, acid and alkali resistance, high temperature resistance, good thermal stability. White corundum is a high-grade abrasive material, and is a senior grinding, polishing materials, etc., with its processing made of abrasive, suitable for grinding hardened alloy steel, high carbon steel, high speed steel and a variety of stainless steel. It is also widely used in fine grain milling precision casting, steel fire, chemical fire, 95 electric porcelain, decorative ceramics and other special ceramics and daily life, as well as military, electronics and other high-tech industries. However, in the smelting will be broken arc, string furnace, blasting and pull the lining of the problem, the following by how to solve these problems:

Broken arc

Features: no current display, no noise, no flash between electrodes.

Cause: the arc rod fixation is not good, the displacement rod taking early melt; feeding too fast, at the immersion breaking current pathway on furnace reaction to form lumps, falling blocked electrode.

Solution: make up before the examination of arc; furnace is stable after the fishing rod; pay attention to the feeding speed on the furnace; Qin movable electrode; re arcing.

Two, string furnace

Feature: melt flow rapidly back and forth in the solid powder material, stirring up lots of alumina, sometimes causing arcing, generally occurs in the start-up after 10h.

The reason is that the material layer is thicker, the bottom surface is small, and the material is not uniform, which leads to uneven heating. When a part of the melt and the wall contact or the pressure inside the furnace is large, the molten liquid is ejected and a large amount of cold material flows into the furnace.

Solution: the first few h with low voltage, expand the melting surface, increase the volume of liquid; severe will lump broken flat charge, thorough treatment.

Three, shooting

Features: the furnace suddenly roared, emits heat, fire without lining, shooting at the furnace shell redness, caused a serious leak.

The reasons are as follows: the furnace bottom, the lining is moist, the raw material is moist, the outside water is immersed, the material layer is too thick, the operation is not proper, and the pressure in the furnace is too large.

Solution: to prevent the bottom of the wet; control of raw water; to strengthen the operation, to ensure uniform material layer; no lining furnace to increase the cooling water; timely treatment, breaking the agglomeration, the formation of charge;

Four, pull the lining"

Features: molten melt reaction and lining, turn over prance material layer, serious, difficult to feed down, or even a leak accident.

Cause: improper operation, uneven feeding or discomfort, electrode material layer is too thin, the electrode is too close to the furnace wall, the voltage is too low.

Solution: in addition to the outer side of the white corundum refractory material, the size of 20 - 40mm; adjust the voltage or electrode distance; reduce the current, reduce the input power, increase the cooling water; if necessary, stop furnace treatment.