Analysis of precipitates in heat treated thermo-mechanically processed steel with a high yield strength

Abstract

Abstract The aim of this study was to analyse the precipitates and determine their impact on the structure of thermomechanically processed high strength S700MC steel. The tested samples were subjected to a heating process at temperatures from 100°C up to 1300°C with a 100°C step. The chemical composition analysis in the micro-areas of the samples, thin-film tests and quantitative measurements of carbonitride precipitates were performed. In order to describe the grain size, a method of calculating the number of grains cut through the measuring line was used. In order to determine the effect of heat treatment on strength and plastic properties, Charpy V-notch, Vickers hardness and static tensile tests were carried out. The study showed that S700MC steel is characterized by a non-equivalent, fine-grained bainitic-ferritic structure. The test showed a significant impact of heat treatment on the strength and plastic properties of S700MC steel.