The Use of Metastable Austenite to Increase the Wear Resistance of Steels of the Pearlite Class

Abstract

The wide application of steel 110G13L for armor plates in mills and crushers makes it urgent to search for alternative materials with close or sufficient operational stability in conditions of shock abrasive wear. A promising path in this direction is the replacement of steel 110G13L with high-carbon pearlitic steels. The aim of this work is a comparative study of the relationship between the structure formed in the heat treatment process of the low-alloyed pearlite steels 70X2GSML and 150HNML and their abrasive wear resistance. Special attention was paid to the possibility of using metastable austenite as a structural component, which increases the abrasive wear resistance of pearlitic steels. It is established that the steel of the pearlite class 70X2GSML, after normalization from 850 °C and tempering at 550 °C, can be used for casting armor plates for ball and rod mills, as well as to cast parts subjected to machining and operating under abrasive conditions without significant impact loads. It is shown that an additional reserve for increasing the abrasive wear resistance of steels of the pearlite class - 70X2GSML and 150XNML - is high-temperature quenching with the formation of a metastable austenite in the structure. The maximum abrasion wear resistance is achieved after the high-temperature quenching of steels (1150 °C) in oil, which forms a martensitic structure with a metastable austenite in the amount of 20-70%, which, with wear, turns into martensite with a high friction hardening ability on the wear surface.

Engineering Method for Analysis of the Ability to Strain-Hardening of Steels

“…It is shown that the curves for both steels and ball diameters have an increasing dependence on the degree of plastic strain similar to the hardening curves for plastic strain compression. This indicates an increase in the strain degree at the bottom of the indentation cups as the indenter load increases [3,9,10].…”

“…This method was used for comparative evaluation of two wear-resistant steels on the basis of stable high-manganese austenite-110G13L and metastable austenitic manganese steel -110G6L. Mechanisms of strain hardening of these steels have been investigated earlier [2][3][4][5].…”

Engineering Method for Analysis of the Ability to Strain-Hardening of Steels

“…The hardness impresses show ferromagneticity when measured with a ferrometer at all loads and diameters on steel samples 60G9Kh4L, while similar hardness impresses are non-magnetic on 110G13L steel samples. This fact indicates the appearance of α-martensite upon indentation of spherical indenters into the surface of metastable austenitic steel 60G9Kh4L, in which the transformation under loading proceeds according to the scheme γ → ε → α [1] and indicates the stability of austenite of 110G13L steel under loading.…”

“…This method was used for comparative evaluation of two wear-resistant steels on the basis of stable high-manganese austenite-110G13L and metastable austenitic chromium-manganese steel -60G9Kh4L. Mechanisms of strain hardening of these steels have been investigated earlier [1].…”

Increasing the Abrasive Wear Resistance of High-Chromium Steel after Cold Treatment

“…The formation of disperse crystals of martensite deformation by the shear mechanism is accompanied by the relaxation of microstrains at the moment of transformation (the micro-triplet effect). As a result of γ → α transformation, the high strength of the working surfaces of steels and their operability in abrasive wear conditions are provided [6].…”