Increasing resource of scraper conveyors

Abstract

We have studied the properties of steels BRK, 18ChGT, 20ChGNB used for the manufacture of sidewalls of chute conveyor pans after various treatment regimes in order to select the most appropriate one. The working conditions stipulate high demands to chute conveyor pan material with respect to strength and durability, and the term of chute conveyor pan service is deter-mined by the sidewall stability. The level of properties, microstructure of sidewalls after thermal treatment as well as the heat treatment and welding are analyzed. As between the hardness and wear resistance there is a direct relationship, the research methodology consisted in measuring the hardness, strength indicators, and study of the microstructure. It was revealed that after the heat treatment and welding of pan sidewalls made of steel BRK there is not provided the desired level of strength (the tensile strength must not be lower than 1275 MPa), and there is observed unevenness in the distribution of hardness and strength properties over the cross section. This can be avoided using alloy steels. It was established that the profiles made of steel 20ChGNB when quenched in oil provide a higher level of properties than profiles made of steel 18ChGT. When welding the sidewalls of pans made of steel 20ChGNB with other parts of pans subject to wear the softening areas do not exceed 2-3 HRC. On the basis of the above studies it should be noted that steel 20ChGNB can be recommended for the manufacture of sidewalls of pans.