The chute lining plate will be seriously worn in daily application. Then, we analyze and compare four common lining plate materials: cast iron, stainless steel, polyethylene molecule and wear-resistant ceramics, and discuss the necessity of widely popularizing wear-resistant ceramic lining plate in iron and steel enterprises in many aspects such as wear resistance, impact resistance and economic benefits.
Sintering plant and coking plant take iron ore, coking coal and coke as production raw materials and transport raw materials for the next process; The 24-hour cycle is adopted, with large flow of iron ore, coking coal and coke and long feeding time, which is easy to cause serious wear of output equipment, especially chute; It is often forced to stop for emergency repair during production, and some chutes are installed in the air more than ten meters and tens of meters high, so it is troublesome to dismantle and replace them; Therefore, it is particularly important to improve the wear resistance and impact strength of chute lining material.
Comparison of properties of common chute lining materials
1. Cast iron liner
Cast iron is a commonly used wear-resistant material in engineering. According to the carbon content, cast iron is divided into three types: gray cast iron, white cast iron and hemp cast iron. When it is used as a lining plate, its hardness is between hb100 and 300. It is hard, but it can not be cut. The lining plate with cast iron as raw material is very brittle and can not bear heavy impact load.
2. Stainless steel lining plate
The material of this steel lining plate is made of molybdenum chromium alloy. Its hardness is 2 or 3 times that of cast iron lining plate, and its service life is 12 times that of cast iron lining plate. It has achieved obvious results in reducing dust and rebound rate and reducing the loss of bonding plate, but its good wear resistance is obtained by continuously hardening its surface under strong impact load, If it does not have enough impact load and the working condition is mainly static friction, its characteristics can not be fully displayed, and its wear resistance is almost the same as that of general medium carbon steel. Moreover, the cost of stainless steel lining plate is high, frequent replacement is easy to cause great waste, and the material is different from the base metal of chute, which is troublesome in welding.
3. Polyethylene molecular liner
Polyethylene molecular material has the characteristics of good wear resistance, low friction coefficient, good sliding performance, corrosion resistance, good insulation performance, light texture, easy processing, good shock absorption and silencing. In the iron and steel industry, it is mainly used for the lining plate on the equipment for conveying magnet powder and coal. It can also prevent noise and play an environmental protection role. The general thickness is 10 ~ 30mm.
4. Ceramic lining plate
In fact, wear-resistant ceramic materials have been widely used in lining plates in Europe and America since the early 1990s. They are mainly used in easily worn mechanical equipment such as material conveying system, dust removal system and ash discharge system in thermal power, steel, smelting, machinery, coal, mining, cement and chemical industries. They mainly use a kind of alumina as the main raw material and supplemented with other ingredients, It is sintered at high temperature up to 1700 ℃. The commonly used wear-resistant ceramic lining plates mainly include planar ceramic patch, spherical ceramic patch, jacketed welded ceramic patch, welded ceramic brick and anisotropic ceramic lining plate. Its properties refer to: alumina content 92%, density 3.6g/cm3, Rockwell hardness 85hra, compressive strength 850mpa, fracture toughness kic4 · 8Mpa · ML2, flexural strength 290mpa, thermal conductivity 20W / m · K and thermal expansion coefficient 7.2 × 10-6m / m · Ko is characterized by good wear resistance, high impact load resistance, high temperature resistance (it can operate between 0 ℃ and 250 ℃ for a long time), good resistance to weak alkali and weak acid, good anti falling performance, easy installation and replacement, ultra-high wear resistance and reduced maintenance times.
