Panchenko A. Increasing of durability of fire grates of traveling grate machines through developing and applying sparingly alloyed electric steel

Thesis is concerned with increasing of durability of fire grates of traveling grate ma-chines for pellet firing and sintering. The timeliness of the work, aimed at increasing of durability of fire grates of traveling grate machines through developing and applying sparingly alloyed electric steel has been shown. The analysis of modern state of technology and equipment of pelletized iron ore production on traveling grate and sintering machines was done. The formation of mineral composition, structure and metallurgical characteristics of pellets and sinter was studied. The composition and operating characteristic of steels used for fire grates in traveling grate machines for pellet firing and sintering was analyzed. Sparingly alloyed steel 30Х14Г8Ю2Л, microalloyed with titanium and nitrogen has been developed in this work. The possibility of using it for fire grates of pellet firing and sintering traveling grate machines has been scientifically grounded. Together with the university fund "Aalto" (Espoo, Finland, 2010) the comparative computer simulation of heat resistance of steels used for the manufacture of fire grates for pellet firing roasting and sintering traveling grate machines and developed steel was performed. Developed aluminum-chrome-manganese steel, microalloyed with titanium and nitrogen is the most preferable both in expected heat resistance, and in terms of choice of more efficient alloying elements. The results of a comparative industrial test of the developed steel 30Х14Г8Ю2Л, microalloyed with nitrogen and titanium and steels currently used on pellet firing and sintering traveling grate machines have been presented. The use of the developed steel for fire grates provides their wear reduction.