Evaluation of Hardness, Sliding Wear and Strength of a Hypoeutectic White Iron with 25%Cr after Heat Treatments

Abstract

Hypoeutectic white cast irons with a high chrome content are commonly used in the industrial mining sector where there is a demand for both high resistance to adhesive wear and an acceptable toughness for the absorption of impacts and falls of diverse materials. Through the application of a design of experiment (DoE) technique, factors related to thermal treatment are analyzed with respect to resistance to sliding wear, maximum rupture stress and toughness. The results show that, in order to increase resistance to adhesive wear, it is convenient to use destabilization temperatures of 1050 °C and tempering of two hours at 400 °C. This foments a very hard martensite and a high proportion of highly alloyed retained austenite, which, with low tempering, achieves a precipitation of carbides from this austenite with hardly any loss of hardness of the martensite. In order to increase the energy which this material is capable of absorbing until breakage, furnace cooling set at 150 °C followed by tempering at 550 °C would be favorable. Slower cooling implies a greater quantity of conditioned retained austenite, so that, following this, it may be transformed into lower bainite with a high density of finely dispersed precipitated carbides. Furthermore, this tempering also allows the transformation of martensite into ferrite with finely dispersed carbides.

The Influence of Hot Deformation on the Mechanical and Structural Properties of 42CrMo4 Steel

“…Steel 42CrMo4 is widely used in the machine building industry, being used in the manufacture of high-strength parts in compressors and turbines, of the working elements in heavy surface and underground equipment, as well as of parts for agricultural equipment and other applications. In general, its application is for statically and dynamically stressed components for engines and machines [1][2][3][4][5][6][7][8][9][10]. Steel 42CrMo4 is a low alloy steel with chromium, molybdenum and manganese, is usually used in a hardened and tempered state and has wide industrial applicability due to its high strength and hardness, good fatigue behaviour and good machinability [9,10].…”

“…In general, its application is for statically and dynamically stressed components for engines and machines [1][2][3][4][5][6][7][8][9][10]. Steel 42CrMo4 is a low alloy steel with chromium, molybdenum and manganese, is usually used in a hardened and tempered state and has wide industrial applicability due to its high strength and hardness, good fatigue behaviour and good machinability [9,10]. Despite the efforts made in studying the behaviour of 42CrMo4 steel, the effects of hot working process parameters on the stress distribution, strain, and microstructural evolution of hot worked 42CrMo4 steel needs to be further investigated to understand its workability and to optimize its parameters at varying temperatures [11,12].…”

Improvements in Wear and Corrosion Resistance of Ti-W-Alloyed Gray Cast Iron by Tailoring Its Microstructural Properties

“…The higher mechanical hardness is based on the higher volume percentage of pearlite, which can resist surface deformation during the wear phenomena [7,8]. Therefore, it is established that the modified microstructure of GCI with a fine grain size, small amount of graphite, and higher pearlite-to-ferrite ratio is the main requirement for achieving better wear resistance [9][10][11].…”

Multi-objective optimization of alloying elements to enhance the wear resistance and impact strength of HCCI produced by furan sand mold

“…17 The bulk hardness of (HCWCI) was increased by adding the alloying element of (0-2.02 wt % Ti), which forms tiny hard TiC particles in proeutectic austenite. 18 The toughness and wear resistance of (HCCI) which contain (18)(19)(20)(21)(22) wt % of Cr and (2-5) wt % of C was increased by adding alloying elements (Mo, Ni and Mn). 19 The effect of alloying element Nb to (HCCI) which contains 4.0 wt % of C, forms refined NbC in the hypereutectic (HCCI).…”

“…The result shows that the hardness and wear resistance increases when tempering is conducted at 400°C. 22 The factorial design (DoE) was developed with 6 factors and 8 experiments to identify the influence of heat treatment parameters on high chromium hypo eutectic white cast iron with the composition of 18.1 wt % Cr, 2.9 wt % C, 1.8 wt % Mo, 1.2 wt % Si and 0.8 wt % Mn. The result shows that the wear resistance increases when the alloy is tempering at 500°C due to an increment in the percentage of martensite.…”