Reconditioning cast iron rolls of the 2000 mill by electroslag surfacing

摘要

In most cases, hot rolling is carried out using steel and cast iron rolling rolls, and the fraction of the latter represents 65 percent of the entire volume of production of rolls. The preferential application of the cast iron and rolls is determined mainly by the higher wear resistance, high-quality surface of rolled material and low production costs, associated with both a relatively low degree of alloying with expensive elements and with the absence of forging of blanks of rolls and, in the majority of cases, by the complicated heat treatment of completed components. It is assumed that the main shortcoming of the cast iron rolls is the lower structural strength of these rolls in comparison with steel rolls. From the viewpoint of the possibilities of reconditioning of cast iron rolls by the methods of arc welding, the cast iron used for the production of rolling rolls is regarded as a material with unsatisfactory weldability. Therefore, if in the case of steel rolls reconditioning arc surfacing was already used more than 50 years ago and is now used in almost all metallurgical companies, the cast iron rolls are taken out of service when the minimum possible barrel shape is formed and sent for remelting, regardless of the fact that the cost of these unique components is tens of thousands of US dollars.