Innovative steelmaking technologies for shaped castings

Abstract

The productivity of the foundry largely depends on the metallurgical stage. When assessing the influence of steel melting technology in acidic and basic furnaces, a connection was established between the technological and strength characteristics of castings: strength and ductility, properties of castings after heat treatment, cracking, etc. These and other differences in properties should be taken into account by specialists developing and preparing technological processes. The introduced and implemented technical, technological and organizational innovations are considered, which provide an increase in the efficiency of electric steel smelting. Among them are the evaluation of the quality of the charge by geometric parameters, pollution of the scrap surface with non-ferrous metals, the need for briquetting and chip packing. Much attention is paid to the physicochemical processes that occur when sulfur and phosphorus are removed from metals. Comparative technical and economic indicators of the operation of electric arc furnaces with acidic and basic lining are given. The main parameters are emphasized: the resistance of an acid lining is almost two times higher than the basic; the acidlined furnace charges off 20% more; the duration of the basic heat is increased by 30–40 minutes in comparison with acidic. Recommendations are given on the selection and calculation of electrodes, the arrangement of electrode holders, and economizers. The technology of steel refining with synthetic slag in a ladle when releasing steel from a furnace is described. Examples of the use of nanomaterials in the modification of steel are given, which makes it possible to obtain castings with a homogeneous fine-grained structure in various sections, and increased operational reliability of cast parts.

Keywords

• electric arc steel smelting
• charge
• acidic and basic melting
• desulfurization
• dephosphorization
• out-of-furnace treatment
• nanomodification