Shallow Cryogenic Treatment (SCT) Effects on the Mechanical Properties of High Cr Cast Iron: Low-Carbon Cast Steel Bimetallic Casting

Abstract

The shallow cryogenic (subzero) treatment (SCT) effect on the mechanical properties of the bimetallic casting used in the crushing industry has been investigated. Examination methods include sand casting, heat treatment and SCT, Charpy impact test, optical microscope, scanning electron microscope, microanalysis of the chemical composition (energy dispersive spectroscopy-EDS), x-ray diffraction, and hardness measurement. Two bimetallic castings (single casting containing two layers, one of low-carbon cast steel-LCCS-back up part and other high Cr cast iron-HCCIworking part) have been prepared by the sand casting method. They have been subjected to diffusion annealing at 1040 °C for 5 h. One of them was quenched in pressurized air till 100 °C and was tempered at 270 °C for 3 h and, and the other one has been subjected to SCT at -84 °C for 24 h and then tempered at 270 °C for 3 h. The impact toughness values before and after SCT are determined five Charpy specimens per point. Hardness values and metallography of samples have been analyzed and compared. A remarkable change was observed in hardness and impact energy/toughness before and after SCT.

Multiphase Microstructure Optimization to Enhance the Mechanical Properties of AISI M35 High‐Speed Steel

“…From the XRD diffraction pattern, RA can be observed in Q in small amounts, but not in other samples. Moreover, Figure 1b reveals that {211} α [ 46 ] diffraction peak in all specimens deviates to the left, indicating lattice expansion. There is a slight movement of {211} α peaks in Q–T and D 5h –T, while {211} α diffraction peaks in Q and D 5h shift to the left severely.…”

“…about DCT focused on PM HSS, [30,46] and few mentioned cast HSS. [22,45] Nevertheless, there are notable differences between cast HSS and PM HSS in terms of their grain size and carbide distribution.…”

“…[ 7,44,45 ] Therefore, only by an understanding of the mechanisms during DCT and the evolution of multiphase microstructures during CHT and DCT, can the enhancements of targeted properties be understood. Furthermore, most research about DCT focused on PM HSS, [ 30,46 ] and few mentioned cast HSS. [ 22,45 ] Nevertheless, there are notable differences between cast HSS and PM HSS in terms of their grain size and carbide distribution.…”

Specifics of physico-mechanical characteristics of thermally-hardened rebar

“…As the result, after these operations it is possible to obtain material of the desired microstructure with specific physical and mechanical properties (Hamid, 2020;Ahaneku et al, 2012). Several scientists (Özdemir, 2021;Ahaneku et al, 2012;Nair et al, 2017;Wang et al, 2018) have identified specific features of thermally hardened steel samples, such as higher Brinell hardness, higher values of yield point and tensile strength and reduced relative elongation. Since the hardening of steel proceeds during short period of time, most of the temperature transformations occur in the outer layer of the steel bar (in the so-called "shell").…”

Enhancing EDM Machining Precision through Deep Cryogenically Treated Electrodes and ANN Modelling Approach

“…The wear, hardness, strength, toughness, and electrical properties of electrodes are enhanced by cryogenic treatment, which also enhances dimensional accuracy [ 29 , 30 ]. Ozdemir [ 31 ] found that a shallow CT at −84 °C increased the toughness, hardness, and wear of Cr-Fe compared to low-carbon cast steel. Senthilkumar and Rajendran [ 32 ] found that shallow cold working improved En 19 steel’s wear properties by 114% and deep cold working by 214%.…”