Effect of Nitrogen on the Impact Toughness of the Bearing Steel GCr15

2011 ◽  
Vol 311-313 ◽  
pp. 948-952
Author(s):  
Ji Chun Yang ◽  
Nan Liu
Keyword(s):  
Impact Toughness ◽  
Large Scale ◽  
Fracture Morphology ◽  
Bearing Steel ◽  
Impact Testing ◽  
Micro Cracks ◽  
Industrial Manufacture ◽  
Nitrogen Concentrations ◽  
Secondary Precipitates ◽  
The Impact

In order to explore the influence of the nitrogen concentrations on the impact toughness of the bearing steel GCr15，impact testing has been conducted on the steel samples with variant nitrogen contents (0.1-0.3 wt.%) on the tester JB－30B, and the fracture morphology of the samples after impact was investigated using scanning electron microscopy (SEM) and optical microscopy (OM). The results indicate that the impact toughness of the steel GCr15 with 0.1 wt.% nitrogen exhibits the lowest values with typical quasi-cleavage feature. The steel GCr15 with 0.2 wt.% nitrogen presents the maximum values in impact toughness associated with significant plastic deformation, suggesting ductile nature. The steel with 0.3 wt.% nitrogen presents a quasi-cleavage feature, and micro cracks observed beside the secondary precipitates. The impact toughness values of the steel with 0.3 wt.% nitrogen are higher than that with 0.1 wt.% nitrogen and lower than with 0.2 wt.% nitrogen. The results are valuable for a large-scale bench marked industrial manufacture of the bearing steel GCr15 with the optimized nitrogen concentrations.

scholarly journals Impact, Hardness and Fracture Morphology of Aluminium Alloy (Al-Si) filled Cobalt Oxide Nanoparticles at Various Stir Casting Temperatures

2021 ◽  
Vol 5 (1) ◽  
pp. 11-20
Author(s):  
Mardy Suhandani ◽  
Poppy Puspitasari ◽  
Jeefferie Abd Razak
Keyword(s):  
Impact Toughness ◽  
Melting Temperature ◽  
Impact Test ◽  
Casting Process ◽  
Fracture Morphology ◽  
Stir Casting ◽  
Impact Testing ◽  
Test Results ◽  
The Impact ◽  
Coo Nanoparticles

The automotive and aviation fields require engineering materials that can save and optimise fuel consumption. Unique characteristics of lightweight, higher strength to weight ratio, good corrosion resistance, and good castability are indispensable for castable metal such as Silicon Aluminium (Al-Si). The mechanical properties of Al-Si could be further improved through the addition of Cobalt Oxide (CoO) nanoparticles during the casting process. The importance and purpose of this study were to determine the impact toughness, hardness and fracture morphology of Al-Si metal alloy filled with 0.015 wt.% CoO nanofiller at the various melting temperature of 750 °C, 800 °C and 850 °C. The stir casting method was utilised considering the most appropriate method for mixing nanoparticles powder into the Al-Si matrix. Three test specimens were prepared for each temperature variation. Impact testing using the Charpy method (ASTM E23-56 T) and hardness testing using Rockwell Superficial HR15T and fracture morphology obtained from impact testing fractures were performed accordingly. The impact test results showed that the Al-Si added with 0.015% CoO at 800 °C of melting temperature possessed the highest impact toughness value of 25.111 x 10-3 Joule mm-2 than the other variations. The hardness test results showed that Al-Si added 0.015% CoO with a melting temperature of 850 °C had the highest hardness value of 79.52 HR15T. The fracture morphology of the impact test in all specimens shows uniform brittle fracture characteristics. It is found that the melting temperature during the stir-casting process of Al-Si has played a significant role in influencing the resulted properties of Al-Si filled CoO nanoparticles metal matrix composites. The selection of an accurate melting temperature for the stir casting process will affect the resulted properties of produced metal composites.

scholarly journals Evaluation of Microstructure and Impact Toughness of Shielded Metal Arc Dissimilar Weldments of High Strength Low Alloy Steel and Austenitic Stainless Steel

2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Misbahu A Hayatu ◽  
Emmanuel T Dauda ◽  
Ola Aponbiede ◽  
Kamilu A Bello ◽  
Umma Abdullahi
Keyword(s):  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Impact Toughness ◽  
Impact Energy ◽  
High Strength ◽  
Impact Testing ◽  
Welding Parameters ◽  
Dissimilar Weld ◽  
Weld Joints ◽  
The Impact

There is a growing interest for novel materials of dissimilar metals due to higher requirements needed for some critical engineering applications. In this research, different dissimilar weld joints of high strength low alloy (HSLA) and 316 austenitic stainless steel grades were successfully produced using shielded metal arc welding (SMAW) process with 316L-16 and E7018 electrodes. Five variations of welding currents were employed within the specified range of each electrode. Other welding parameters such as heat inputs, welding speeds, weld sizes, arc voltages and time of welding were also varied. Specimens for different weld joint samples were subjected to microstructural studies using optical and scanning electron microscopes. The impact toughness test was also conducted on the samples using Izod impact testing machine. The analysis of the weld microstructures indicated the presence of type A and AF solidification patterns of austenitic stainless steels. The results further showed that the weld joints consolidated with E7018 electrode presented comparatively superior impact energy to the weldments fabricated by 316L-16 electrode. The optimum impact energy of E7018-weld joints (51J) was attained at higher welding heat inputs while that of 316L-16-weld joints (35J) was achieved at lower welding heat inputs, which are necessary requirements for the two electrodes used in the experiment. Hence, the dissimilar weld joints investigated could meet requirement for engineering application in offshore and other critical environments.Keywords—Dissimilar metal weld, heat input, impact toughness, microstructures

Effect of Grain Size and Meso-Texture on the Impact Toughness of Ti-Microalloyed Steel

2011 ◽  
Vol 702-703 ◽  
pp. 766-769 ◽  
Author(s):  
A. Ray ◽  
Debalay Chakrabarti
Keyword(s):  
Particle Size ◽  
Grain Size ◽  
Impact Toughness ◽  
Microalloyed Steel ◽  
Charpy Impact ◽  
Impact Testing ◽  
Grain Sizes ◽  
Matrix Strength ◽  
Charpy Impact Testing ◽  
The Impact

Charpy impact testing (over the transition temperature rage) on different samples of a Ti-microalloyed steel, having the same average-TiN particle size but different average-ferrite grain sizes, showed that in spite of the presence of large TiN cuboides, ferrite grain refinement can significantly improve the impact toughness, provided the meso-texture (i.e. the intensity of low-angle boundaries) and matrix strength can be restricted to low values.

Effect of Tempering Temperature on Mechanical Properties of High Strength Wear Resistant Cast Steel

2013 ◽  
Vol 791-793 ◽  
pp. 440-443
Author(s):  
Hong Bo Li ◽  
Jing Wang ◽  
Han Chi Cheng ◽  
Chun Jie Li ◽  
Xing Jun Su
Keyword(s):  
Mechanical Properties ◽  
Impact Toughness ◽  
Cast Steel ◽  
High Strength ◽  
Fracture Morphology ◽  
Temperature Quenching ◽  
Tempering Temperature ◽  
Wear Resistant ◽  
Dimple Fracture ◽  
The Impact

This paper mainly studied the high temperature quenching oil quenching, tempering temperature on the influence of high strength steel mechanical properties of wear resistant. The results show that high strength and toughness wear-resistant cast steel with 880°C× 30min after oil quenching, the hardness of 38.6HRC steel, the impact toughness value reaches 40.18J/cm2. After 200°C, 400°C and 600°C tempering, with the increase of the tempering temperature, the hardness decreased linearly, as by 600°C tempering, the hardness has been reduced to 22.3HRC. Impact toughness with the tempering temperature, the overall upward trend, the impact toughness of some reduced at 400°C, the highest impact toughness value reaches 113.34J/cm2. From the fracture morphology can be seen, with the increase of tempering temperature, ductile fracture increased, by 600°C tempering is dimple fracture, obviously can not see the traces of brittle fracture.

Impact Performance of ZnAl27Cu2.5MgMn Alloy from Room Temperature to 250°C

2014 ◽  
Vol 915-916 ◽  
pp. 597-601
Author(s):  
Ming Long Kang ◽  
Wu Hu ◽  
Jian Min Zeng
Keyword(s):  
Impact Toughness ◽  
Impact Energy ◽  
Room Temperature ◽  
Impact Testing ◽  
Impact Behavior ◽  
Impact Performance ◽  
Temperature Impact ◽  
Spectrum Curve ◽  
The Impact ◽  
Pendulum Impact

The impact performance of ZnAl27Cu2.5MgMn alloy from room Temperature to 2500 °C has been investigated by pendulum impact testing. The surface morphology of impact fracture is observed by scan electron microscope (SEM). The results indicate that impact energy of the alloy decreases as the temperature increases when the temperatures are lower than 100°C. Between 100°C and 200°C, impact energy increases as the temperature increases. And when the temperature exceeds 250°C, impact energy decreases dramatically. Impact energy gets to the maximum at room temperature. Impact behavior of the alloy can be evaluated by the width of impact spectrum curve. The wider the peak of impact spectrum curve, the higher the impact toughness. Whereas impact toughness is worse if peak is narrow.

Microstructure and Mechanical Properties of Joints of X100 Line Pipe by Submerged Arc Welding

2013 ◽  
Vol 310 ◽  
pp. 139-144 ◽  
Author(s):  
Min Zhang ◽  
Liang Yang
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Shear Fracture ◽  
Pipeline Steel ◽  
Testing Machine ◽  
Fracture Morphology ◽  
Impact Testing ◽  
Granular Bainite ◽  
Line Pipe ◽  
The Impact

The microstructure, mechanical properties, fracture morphology and crystal texture of pipeline steel X100 welded joints were investigated using optical electron microscope, scanning electron microscope, tensile and impact testing machine. The results show that, the texture of X100 line pipe mainly consists of acicular ferrite and granular bainite in weld zones, the microstructure of HAZ is coarser, which lead to softening and embrittlement. The fusion line is clear between outer weld and inner weld. The tensile strength of welded joint gets to 803 MPa, which is about 94.81% of the base materials. The impact energy at -10°C is more than 120J, and the average of percent shear fracture appearance at -10°C is up to 85%, is ductile fractures.

scholarly journals Heat Treatment, Impact Properties, and Fracture Behaviour of Ti-6Al-4V Alloy Produced by Powder Compact Extrusion

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3824 ◽  
Author(s):  
Singh ◽  
Yang ◽  
Torrens ◽  
Gabbitas
Keyword(s):  
Impact Toughness ◽  
Powder Compact ◽  
Fracture Behaviour ◽  
Hot Extrusion ◽  
Impact Testing ◽  
Vacuum Sintering ◽  
Blended Powder ◽  
Heat Treated ◽  
Processed Material ◽  
The Impact

The mechanical properties of titanium and titanium alloys are very sensitive to processing, microstructure, and impurity levels. In this paper, a blended powder mixture of Ti-6Al-4V alloy was consolidated by powder compact extrusion that involved warm compaction, vacuum sintering, and hot extrusion. The as-processed material with an oxygen content of 0.34 wt.% was subjected to various annealing treatments. The impact toughness of heat-treated material was determined using Charpy V-notch impact testing at room temperature. An emphasis was placed on establishing a relationship among fracture behaviour, microstructure, and the resulting properties of tested material. From the results, it is apparent that the highest impact toughness value of 19.3 J was achieved after α/β annealing and is comparable with typical values given in the literature for wrought Ti-6Al-4V. In terms of fracture behaviour, it is quite apparent that the crack propagation behaviour of powder-produced material is rather complex compared with the limited amount of data reported for ingot counterparts.

Impact Toughness of Kenaf Powder, Polypropylene and Kevlar

2013 ◽  
Vol 393 ◽  
pp. 152-155 ◽  
Author(s):  
Nur Kamarliah Kamardin ◽  
Yakub Md. Taib ◽  
Anizah Kalam
Keyword(s):  
Impact Toughness ◽  
Maleic Anhydride ◽  
Weight Ratio ◽  
Impact Testing ◽  
Hot Press ◽  
Polypropylene Composite ◽  
Optimum Weight ◽  
Drop Tests ◽  
Izod Impact ◽  
The Impact

mpact and tensile properties were carried out on Kenaf Powder (K) Polypropylene (PP) reinforced with Kevlar (KV) composites plate prepared in-house using hot press technique. The effect of bonding agent, Maleic Anhydride grafted Polypropylene (MAPP), on the strength and impact toughness was also conducted. The size of kenaf powder used was limited to 100μm. The kenaf/polypropylene composite designated as KPP specimens were tested through tensile test (ASTM D 638) and izod test (ASTM D256) for 20-40% weight ratio of kenaf powder. The optimum weight ratio of KPP sample was selected and then underwent for the drop impact testing. The selected KPP sample was further reinforced with Kevlar cloths. This hybrid composite is designated as KPP/KV sample and further tested in izod impact and drop tests. The impact toughness of KPP reinforced with KV is almost 4-6 times without KV. There are also slight improvements in the impact toughness of the KPP/KV samples with MAPP.

Effect of Temperature on Impact Properties of ZA27 Alloy

2012 ◽  
Vol 476-478 ◽  
pp. 75-80 ◽  
Author(s):  
Li Ping Zhong ◽  
Jia Yong Si ◽  
Zi Qiao Zheng
Keyword(s):  
Impact Toughness ◽  
Fracture Surface ◽  
Impact Energy ◽  
Impact Testing ◽  
Impact Fracture ◽  
Impact Behavior ◽  
Effect Of Temperature ◽  
Za27 Alloy ◽  
Different Temperatures ◽  
The Impact

The impact toughness of ZA27 alloy at different temperatures is investigated by pendulum impact testing. In addition, the morphology of impact fracture surface observed by SEM. The results indicate that impact energy of ZA27 alloy is reduced with the temperature rising when the temperature is lower than 100°C. At 100°C to 200°C, impact energy increase as the temperature rising. And when the temperature reaches to 250°C, impact energy suddenly descend. Impact energy is the highest and reaches to 72.768J at 20°C. At impact fracture surface, it is mostly tear ridges and dimples. The higher the impact energy is, the more obvious the characteristic of tear ridges is. Furthermore, dimples are small and distribute more uniformly. Lower the impact energy, the less distinct of tear ridges. Dimples are larger and deeper, their distribution are not uniform. Impact behavior of material could be evaluated by the width of impact curve. The wider the peak of impact curve, the higher the impact toughness. But impact toughness is worse while peak is narrow.

Low Temperature Mechanical Properties of Power Transmission Tower Steel

2017 ◽  
Vol 898 ◽  
pp. 772-777
Author(s):  
Jia Xing Wang ◽  
Xu Ming Wang ◽  
Hui Guo ◽  
Ai Min Zhao ◽  
Liu Wei
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Impact Toughness ◽  
Large Scale ◽  
Rolling Direction ◽  
Vertical Direction ◽  
Total Elongation ◽  
Transmission Tower ◽  
Weld Region ◽  
The Impact

The tensile and impact tests were used to study the mechanical properties under different temperatures of 300 mm large-scale angle steel at different positions, especially the tensile strength, yield strength, total elongation and impact toughness in the range of-40 oC to 20 oC. The results showed that different regions had great differences in the microstructures and impact toughness, in which the size of edge region was the smallest and the impact toughness was the best. However, the coarsened grain of heat affected zone at weld region had deteriorated to the low temperature impact toughness. When the impact energy was 34 J, the ductile-brittle transition temperature of weld, center, vertex and edge were-7.2 oC, -33.0 oC, -31.5 oC and far less than-40 oC, respectively. Meanwhile, because the banded structure was detrimental to the ductility, the elongation of rolling direction was lower than vertical direction. The strength of weld region was higher than other locations, but the elongation was obviously decreased.

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