Characteristics of heat-resistant low-alloy cast iron for molds in the glass container industry

Abstract

The growth of national production of glass packaging products requires the use of new materials and technologies to create conversion conditions for the production of moulds and their introduction into production to replace similar imported products.

The main problem faced by glass packaging manufacturers when operating moulding systems is their low service life and failure due to cyclic exposure to high temperatures. The operating environment of a moulding set is caused by the aggressive action of glass material with high adhesive properties, which, in long-term contact, causes defects on the surface of the moulds in the form of oxidised areas and cracks

The high moulding speed and temperature of the aggressive working environment prompts the correction of mould properties, specifically the selection of a chemical composition of a material with a low content of alloying elements, which will improve the performance characteristics of moulds and economic indicators of production.

The paper presents the preparation of the chemical composition of low-alloy cast iron, determines its critical points of phase transformation, establishes its heat resistance characteristics, and recommends it for use as a moulding material.

The results of the differential thermal analysis show that the onset of phase transformations in the experimental cast iron is 17.7 °C higher than the critical point of the sample from the disused mould. The change in the specific mass of the samples after 50 hours of scale resistance tests was determined, which is at a high level and amounts to 0.164 g/(cm²·h).

It has been identified that the growth resistance of cast iron has linear dependencies with increasing influence of cycles, which indicates the absence of sharp phase transformations and, as a result, the absence of dynamic changes in the material during operation. It was identified that the destruction of the experimental cast iron samples occurs at the 60th cycle of high test conditions, which demonstrates positive crack resistance and the presence of a stable structure of the experimental cast iron.