High strength anti-fatigue pellet chain grate grid plate and production process thereof

Abstract

The invention provides a high strength anti-fatigue pellet chain grate grid plate and a production process thereof, and relates to the technical field of production of a chain grate grid plate used in the new pellet steel smelting process. The plate body consists of the elements of Fe, C, Si, Mn, Cr, Mo, Ni, W, Al, V, P and S. The chain grate grid plate formed by using the raw materials has the characteristics of high heat resistance, wear resistance, fatigue resistance and oxidation resistance, reasonable expansion coefficient, long service life and the like.

Description

technical field [0001] The invention relates to the technical field of production of a chain grate plate used in a novel pelletizing process for iron and steel smelting. Background technique [0002] According to the results of expert investigation and research, the grate plate of the pelletizing grate is repeatedly thermally cycled at a working temperature of 200°C to 1050°C (the cycle is 50 cycles / 24 hours); therefore, the thermal fatigue performance requirements of the grate plate of the grate It is extremely high, and has strict requirements on its high temperature wear resistance, oxidation resistance, expansion coefficient and thermal stress. Although some domestic manufacturers currently change the geometric structure or material of the grate plate of the chain grate, or use lost foam manufacturing, or use laser shock strengthening technology and "QPQ" salt bath composite treatment and laser cladding and other technologies, they cannot solve the problem of the grate p...

AI Technical Summary

Problems solved by technology

Although some domestic manufacturers currently change the geometric structure or material of the grate plate of the chain grate, or use lost foam manufacturing, or use laser shock strengthening technology, "QPQ" salt bath composite treatment and laser cladding and other technologies, they cannot solve the problem of the grate plate. Under the condition of repeated thermal cycle at 200℃~1050℃, it is very easy to produce thermal cracks and material oxidation defects

Thermal cracks continue to expand under the action of further thermal stress, eventually causing the grate plate to break; material oxidation eventually leads to the change of the geometric size of the grate plate, and it is easy to leak iron shot or impurities, causing the grate machine to be stuck or shut down

At the same time, due to the lack of rationality in the design of the geometric structure of the grate plates of some domestic manufacturers, bolts are required to fix them during installation, and installation or maintenance is labor-intensive and time-consuming.

The above-mentioned defects of the grate plate cause the service life of the grate plate to be short, and the installation or maintenance is labor-intensive and time-consuming