ESTABLISHING REASONS FOR PREMATURE WITHDRAWAL OF THE GRADER KNIFE MADE OF 110G13X2BRL STEEL IS OUT OF ORDER

PHTEQI

Abstract

Gadfield's high-manganese austenitic steel is made of iron with a carbon content of 1.0 – 1.4 wt.% and manganese – 10-14 wt.% (usually with a ratio of:Mn = 1:10). The paper presents the results of the analysis of 110G13X2BRL steel (grader knife lining material), which allow us to understand the influence of metallurgical quality on the phase structure of steel and its mechanical properties. In the course of research, in particular, it was established that the chemical composition of the steel in the studied casting "grader knife plate" does not meet the requirements of GOST 977 88; steel has an unacceptable liquation of the main components of the alloy (silicon and manganese) along the casting section, one of the reasons for which is, firstly, an incorrect gate system, which should have provided a laminar flow of metal into the mold, rather than a turbulent one, and secondly, an incorrect choice of technological parameters of homogenizing annealing or its absence in principle. In addition to the above, it is also likely that the slag in the bucket was not removed (or a bucket was used that was different from the kettle or lock type buckets, which were supposed to be used when casting such steels), and also, most likely, that the original part of the gating system was missing, which was supposed to feed the casting. This, in turn, manifested itself in the presence of defects such as shrinkage pores. On this basis, it is possible to select the appropriate technological operations to eliminate defects in the microstructure of cast steel 110G13X2BRL.