Effect of Microstructure and Mechanical Properties on Two Body Abrasive Wear Resistance of Medium-Carbon Low-Alloy Steel

2011 ◽  
Vol 52-54 ◽  
pp. 1247-1252 ◽  
Author(s):  
Jun Miao ◽  
Li Jun Wang ◽  
Chun Ming Liu
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Impact Toughness ◽  
Abrasive Wear ◽  
Alloy Steel ◽  
Water Quenching ◽  
Low Alloy Steel ◽  
Tempering Temperature ◽  
Medium Carbon ◽  
Test Steel

The effect of microstructure and mechanical properties on abrasion resistance of the medium-carbon low-alloy steel has been investigated under two body abrasive wear conditions. The results show that the microstructure of the test steel is mastenite and bainite/mastenite when the specimen subjected to water quenching and blow cooling respectively. The hardness of the test steel was over 52HRC when the specimen subjected to water quenching and blow cooling, however, effect of tempering temperature on hardness is slightly. The strength of the test steel is increased with the tempering temperature increased and the impact toughness change slightly under the blow cooling condition. The tensile strength of the test steel is decreased and the yield strength is increased with the tempering temperature increased when the specimen subjected to water quenching and followed tempering. The wear rate is increased with load and the wear mechanism is micro-cutting and microploughing. The wear resistance of bainite/martensite is better than single-phase martensite. The hardness and impact toughness are important factor under two body abrasive wear condition.

scholarly journals Influence of Charge Quality on Physical, Mechanical and Operational Properties of Low-Alloy Steel 30KHGSA

2020 ◽  
Vol 24 (2) ◽  
pp. 17-36
Author(s):  
N. N. Sergeev ◽  
A. N. Sergeev ◽  
S. N. Kutepov ◽  
I. V. Tikhonova ◽  
A. E. Gvozdev ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Impact Toughness ◽  
Alloy Steel ◽  
Relative Elongation ◽  
Temper Brittleness ◽  
Low Alloy Steel ◽  
Cross Sectional ◽  
Tempering Temperature ◽  
Working Length ◽  
The Impact

Purpose of reseach is to study the influence of the quality of the original charge on the complex of physical, mechanical and operational properties of structural low-alloy steel 30HGSA.Methods. As an object of research, a typical representative of low-alloy structural steels has been chosen - steel 30HGSA, smelted using metallized sponge iron pellets, ordinary scrap metal and billets obtained by the method of a boiling slag layer. In accordance with the set objectives of the study, steel 30HGSA of various melts, obtained with different charge, had the same conditions for melting, evacuation, deoxidation, casting and crystallization. The casting temperature was 1600...1620 оC and the post-vacuum treatment temperature was 1530...1560 °C. Duration of evacuation - 5 minutes. Casting of melts was carried out into cast iron molds with a siphon for 4 ... 5 minutes. Deoxidation was carried out in a ladle with aluminum in the amount of 4 ... 4.5 kg / melt. After solidification, the ingots were cooled in special wells. The ingots were cut into 3 parts: head, middle and bottom (600 × 600 mm). The middle part was then hot forged and rolled to a Ø30 mm bar. The length of the rod was 2 ... 3.4 m. After hot deformation, the rods were cooled in air.Results. Mechanical tests have been carried out. Statistical processing of experimental results has been performed. Regularities of changes in the characteristics of mechanical properties have been revealed: tensile strength, creep strength, relative narrowing of the cross-sectional area of the sample, relative elongation of the initial working length, impact strength (σВ, σ0.2, ψ, δ, aН).Conclusion. It has been found that with an increase in temperature, the mechanical properties of steel 30HGSA, smelted on various charges, decrease. It has been established that the cold brittleness threshold of 30HGSA steel is lower for purer melts on spongy iron and intermediate product KShS, the value of impact toughness at low temperatures is higher than in melting on a conventional metallized charge. Noticeable softening begins at a tempering temperature of 300 °C The temperature of the maximum tempering brittleness for steel 30HGSA, melted on a conventional metallized charge, is 550 °C It is shown that steel 30HGSA smelted with a pure original charge (spongy iron) has a lower tendency to temper brittleness than steel smelted with a conventional charge. The value of the impact toughness of the steel of this melt is higher than that of the steel of conventional melting over the entire tempering temperature range.

Investigation of Microstructure and Mechanical Properties of Ultra High Strength Bainitic Steel

2013 ◽  
Vol 313-314 ◽  
pp. 77-81
Author(s):  
M.H. Sheikh Ansari ◽  
M. Aghaie-Khafri
Keyword(s):  
Mechanical Properties ◽  
Alloy Steel ◽  
High Strength ◽  
Lower Bainite ◽  
Good Combination ◽  
Bainitic Steel ◽  
Low Alloy Steel ◽  
Tempered Martensite ◽  
Medium Carbon ◽  
Bainitic Steels

In this study, medium carbon low alloy steel was used to obtain bainitic structures. The lower bainite and tempered martensite-lower bainite structures were achieved by isothermal austempering and up quenching treatment, respectively. Based on the results obtained these structures showed a very good combination of strength and toughness. Furthermore, it has been shown that austenitization time and temperature, as well as austempering time and temperature play a major role in achieving ultra-high strength bainitic steels.

Mechanical Properties of a Medium Carbon Low Alloy Steel Processed by Two Step Austempering Process

2010 ◽  
Vol 638-642 ◽  
pp. 3453-3458 ◽  
Author(s):  
Susil K. Putatunda ◽  
Abhijit Deokar ◽  
Gowtham Bingi
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Yield Strength ◽  
Alloy Steel ◽  
High Yield ◽  
Bainitic Steel ◽  
Low Alloy Steel ◽  
High Yield Strength ◽  
Medium Carbon

A new bainitic steel with a combination of exceptionally high yield strength and fracture toughness has been developed. This steel has been synthesized by austempering a medium carbon low alloy steel by a novel two-step austempering process. The influence of this two-step austempering on the microstructure and the mechanical properties of this new steel have been examined.

Effect of Thermomechanical Treatment on Mechanical Behaviour and Microstructure of Low Alloy Steel

2012 ◽  
Vol 184-185 ◽  
pp. 838-849
Author(s):  
Mahmoud M. Tash
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Impact Toughness ◽  
Alloy Steel ◽  
Mechanical Behaviour ◽  
Hot Forging ◽  
Weight Ratio ◽  
Ultimate Tensile Stress ◽  
Low Alloy Steel ◽  
Strength And Ductility

The present study was undertaken to investigate the effect of thermo-mechanical treatment (TMT) on the microstructure and mechanical behaviour of low alloy steel. Hot forging is carried out at 1200°C using mechanical press of 500 and 800 ton. The effect of hot forging reduction ratios (1.11 and 1.29) on the hardness and mechanical properties are studied. TMT samples are given different heat treatment i.e. annealing (A), normalizing (N), hardening (H), hardening and tempering (H/T) and their corresponding impact toughness are obtained. Selected heat treatment (normalizing and annealing) are given to tensile test samples and their corresponding strength and ductility are obtained. Ultimate tensile, 0.2% offset yield strength and percent elongation are measured. Hardness and impact toughness measurements were carried out for all alloy conditions. Hardness (HV), ultimate tensile stress (UTS-MPa) and 0.2% offset yield stress (MPa) increases with increasing reduction ratio. TMT leads to a sharp rise in alloy hardness and strength. Normalizing and annealing following TMT revealed a low hardness values compared to those observed in the TMT condition. Annealing reduces hardness and strength but increases ductility and impact toughness. This could be attributed to the recovery and coarsening effect. Pro-eutectoid ferrite phase are observed along the grain boundaries of low alloy steel in the TMT conditions regardless of the reduction ratios. Normalized samples show a refined pearlitic microstructure while coarse pearlite is observed in the annealed one. Good mechanical properties can be obtained by a combination of plastic deformation and thermal treatment. Heat treatment is one of the major factors used to enhance the mechanical properties of low alloy steel. An understanding of the combined effect of TMT and subsequent heat treatment on the structure and mechanical properties of low alloy steel would help in selecting conditions required to achieve the optimum mechanical properties and alloy high strength to weight ratio. This may be achieved by measuring hardness, impact toughness, strength and ductility resulting from different heat treatment following TMT.

scholarly journals Improvement of Impact Toughness and Abrasion Resistance of a 3C-25Cr-0.5Mo Alloy Using a Design of Experiment Statistical Technique: Microstructural Correlations after Heat Treatments

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 595
Author(s):  
Alejandro González-Pociño ◽  
Juan Asensio-Lozano ◽  
Florentino Álvarez-Antolín ◽  
Ana García-Diez
Keyword(s):  
Wear Resistance ◽  
Impact Toughness ◽  
Abrasive Wear ◽  
Design Of Experiment ◽  
Retained Austenite ◽  
Statistical Technique ◽  
Cast Irons ◽  
Slow Cooling ◽  
Tempering Temperature ◽  
The Matrix

Hypoeutectic high chromium white cast irons are commonly used in the mining and cement industries, where high resistance to abrasive wear is demanded. Through the application of a Design of Experiment technique (DoE), different factors related to thermal industrial treatments are analysed with regard to resistance to abrasive wear and impact response. Abrasion tests were carried out in accordance with the ASTM G065-16 standard. The provisional results show that to increase wear resistance, high destabilisation temperatures (1050 °C) followed by slow cooling to room temperature (RT) and subsequent tempering at 400 °C are most favourable. This is because these conditions are favourable to maintaining a certain tetragonality of the martensite after tempering and also, because of the presence of a high density of mixed carbides M7C3, through a secondary precipitation during cooling. Oil quenching and a high tempering temperature (550 °C) with long dwell times of 6 h were found to increase impact toughness. These conditions favour a lack of retained austenite. The presence of retained austenite was found unfavourable for both wear resistance and toughness, whereas tempering at 400 °C has been shown to be insufficient to transform martensite on tempering, which in turn seemed to increase the hardness of the matrix constituent.

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