Abrasion resistance of high Mn steel alloys

PRIETO, GERMÁN; RABBIA, GONZALO RODRIGO; TUCKART, WALTER ROBERTO; MONSALVE, ALBERTO

Mar del Plata

Workshop; 3rd Workshop of Tribology; 2015

Asociación Argentina de Tribología - Universidad Nacional de Mar del Plata

High Mn steel alloys had been used since its discovery by Sir Robert Hadfield in 1882 in heavy duty applications, where high strength and bothhigh impact and abrasion resistance is required. This steels are commonly used in mining equipment, cement mixers, ore mills and in ground engaging tools. This group of alloys deform not only by dislocation slip but also by displacive deformation mechanisms. These mechanisms are characterized by a diffusionless collective motion of clusters of atoms where each atom is shifted by only a small distance relative to its neighbors, being mechanical twinning the most common of them. Hadfield steels, also known as Mangalloys, are steel alloys containing 0.8 to 1.25% C and Mn between 11 to 15%. The high content of Mn inhibites the ferritic transformation at room temperature. For thisreason, Hadfield steels exhibit an austenitic microstructure and therefore high toughness and strain-induced hardening.A recently developed family of high Mn alloys are the so-called Twinning-Induced Plasticity (TWIP) Steels. This alloys have higher Mn contents than Hadfield steels (above 20 %wt) and lower carbon contents, being usually below 1 C %wt. TWIP steels exhibit very promising properties, specially those regarding toughness, tensile strength and strain hardening. The automotive industry is showing increasing interest in this alloys due to their ability to absorb high amounts of energy during impacts and collisions. As TWIP steels are considered an evolution fromtraditional Hadfield steels [1], it is interesting to evaluate their tribological properties, specially under both abrasion and impact-abrasion conditions. For this purpose, wet slurry and Los Angeles impact-abrasion tests were performed in order to determine the wear resistance of the materials.