Simulation of the Hot Flow of C80 Steel intended for the AISI1080 Strength Rank Bar

Djamel Berdjane, Rachid Benchouieb, Badreddine. Maalem, Ali. Hafs, Toufik Hafs, Sihem. Achouri, Chems Eddine. Ramoul

The objective of this study is to provide data on the mechanical properties of high-carbon C80 steel intended for the manufacture of working tools and to develop a comprehensive understanding of their microstructural evolution in terms of deformation parameters. This steel is known for its wear resistance and toughness, and is also ideal for manufacturing bearings and other wear parts produced in industrial processes. More specifically, the main objective is to develop a material with a better balance of properties from unalloyed steel in order to expand production to AISI 1080 grades using the same chemical composition. To this end, empirical tests, including hot tensile testing (within range of strain rates), were carried out to simulate the rolling sequences of the industrial process. The results of these experimental protocols have highlighted the significant effect of deformation parameters on the evolution of the final microstructure, and therefore on the mechanical properties of the steel studied. This has also led to technological proposals for obtaining high grades for this type of AISI 1080 rolled steel. The prediction of the evolution of the austenite microstructure during hot deformation, a key step in modelling phase transformations, has also been developed to more accurately predict grain size as well as the associated critical strains and stresses. These various investigations will allow us to develop flow property prediction approaches based on analytical aspects and microstructural observations in order to determine quantitative relationships between macroscopic constitutive laws while describing the physical phenomena underlying rheological behaviour. Hot working simulation tests were performed by uniaxial tensile testing in order to obtain the stress-strain flow curve for C80 is a high carbon rolled steel. This will be validated by comparing its predicted load-elongation curves with the experimental results of the tensile tests. Subsequently, a numerical model validated using the JMat Pro software was used to analyze the load distribution between the samples in roughing mill at various temperatures (1000 ̊C, 1050 ̊C, 1100 ̊C) and under strain rates (0.001, 0.01, 0.1, 1, 10 s-1). This approach made it possible to predict the deformation mechanisms and the progression of hot plastic deformation leading to the final on determines the flow stress at constant strain rates C80 steel. The aim of this work is to study the combined influence of temperature, and strain rate on the hot rheological behavior of C80 steel and the mechanisms that govern them.