Tempering Temperature Effects on Hardness and Impact Toughness of 56NiCrMo7 Steel

2011 ◽  
Vol 56 (1) ◽  
pp. 5-11 ◽  
Author(s):  
R. Dąbrowski ◽  
R. Dziurka
Keyword(s):  
Impact Toughness ◽  
Tool Steel ◽  
Impact Energy ◽  
Temperature Effects ◽  
Test Specimen ◽  
Impact Test ◽  
Test Results ◽  
Tempering Temperature ◽  
Fracture Surfaces ◽  
The Impact

Tempering Temperature Effects on Hardness and Impact Toughness of 56NiCrMo7 Steel The assessment of the effect of tempering temperature on hardness and impact toughness of a 56NiCrMo7 grade hot work tool steel was presented in the paper. It has been found that the investigated steel, after quenching in oil from 800°C, softens quite slowly upon tempering within the range between 100 and 675°C, which was confirmed not only by hardness measurements but also by observed changes occurring in its microstructure, whereas the impact energy (KV) absorbed by the test specimen increases with temperature, achieving >66J after tempering at 675°C. The changes observed in the character of the fracture surfaces allows of interpretation of the impact test results for the whole range of tempering temperatures.

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.

Impact Toughness of 0.3 Mass% Carbon Tempered Martensitic Steels Evaluated by Instrumented Charpy Test

2014 ◽  
Vol 783-786 ◽  
pp. 1033-1038
Author(s):  
Shigeto Takebayashi ◽  
Kohsaku Ushioda ◽  
Naoki Yoshinaga ◽  
Shigenobu Ogata
Keyword(s):  
Impact Toughness ◽  
Temperature Dependence ◽  
Impact Energy ◽  
Charpy Impact ◽  
Waveform Analysis ◽  
Charpy Impact Energy ◽  
Martensitic Steels ◽  
Tempering Temperature ◽  
Wide Range ◽  
The Impact

The effect of tempering temperature on the impact toughness of 0.3 mass% carbon martensitic steels with prior austenite grain (PAG) size of about 6 μm and 30 μm were investigated. Instrumented Charpy impact test (ICIT) method was used to evaluate the impact toughness. The tempering temperature of 723K gives the largest difference in the Charpy impact energy at room temperature (RT) between the specimens with two different PAG sizes. Investigation of the test temperature dependence of Charpy impact energy in the 723K tempered steels shows a steep transition at around 200 K for the 6 μm PAG specimen, while it shows a continuous slow transition in a wide range of temperature for the 60 μm PAG specimen. ICIT waveform analysis shows that the fracture propagation energy in stead of the fracture initiation energy mainly controls the temperature dependence of the impact energy. The carbide size distribution in these two specimens was investigated by SEM and TEM. The 60 μm PAG specimen shows the distribution of coarser carbides than does the 6 μm PAG specimen, which seems to be the main reason for the observed difference between them in the Charpy impact energy and the other properties of impact fracture.

scholarly journals Study impact toughness on polyester matrix composite fiberglass reinforced Musa acuminata stem fibers as raw material of rear bumper vehicle

2020 ◽  
Vol 5 (3) ◽  
pp. 094-098
Author(s):  
Sujita Darmo Darmo ◽  
Rudy Sutanto Sutanto
Keyword(s):  
Impact Toughness ◽  
Matrix Composite ◽  
Impact Energy ◽  
Impact Test ◽  
Volume Fraction ◽  
Natural Fibers ◽  
Musa Acuminata ◽  
Raw Material ◽  
Polyester Matrix ◽  
The Impact

The use of natural fibers as composite reinforcement has various advantages, including as substitute for artificial fiber, low price, able to reduce sound, environmentally friendly, has low density, good fit and ability to absorb impact energy, making it possible to use it as a vehicle accessory such as a rear bumper vehicle. This study aims to investigate the impact toughness performance of the fiberglass matrix composite polyester (FMCP) reinforced fiber Musa acuminata stem fiber (MASF), with a volume fraction of 5%, 10%, 15%, 20% and 25%. Polyester matrix type 157 is used BQTN and G3253T, MEKPO catalyst. The impact toughness test was carried out by using the charpy method impact test instrument, observing the microstructure of the occurrence of fracture by using scanning electron microscope (SEM). The composite impact test specimen was 12.7 thick mm refers to the ASTM D 256 standard, produced by the hand layup method. The most optimal volume fraction impact test at a volume fraction of 20% MASF: 80% Matrix, with an impact energy of 14.47 J, impact toughness 0.094 J/mm2. The results showed that the addition of MASF increased the impact toughness of the composite by 14.69% compared to composites 0.0122 J/mm2. Based on SEM observations, it can be seen that the 20% MASF volume fraction of the bonds between the matrix and the fibers are perfectly integrated. The results showed that the addition of MASF increased the impact toughness of the composite by 14.69% compared to composites 0.0122 J/mm2. However, if a volume fraction ratio above 20% MASF is used, the impact toughness is decreased.

Effects of Annealing Process on Mechanical Properties of Weather-Resistant Steel Welding Joints

2018 ◽  
Vol 777 ◽  
pp. 397-401
Author(s):  
Qiang Zhang ◽  
Zhe Wu ◽  
Hong Wu Li
Keyword(s):  
Mechanical Properties ◽  
Impact Energy ◽  
Welded Joints ◽  
Impact Test ◽  
Resistant Steel ◽  
Test Results ◽  
Before And After ◽  
Welding Joints ◽  
Weld Area ◽  
The Impact

In this paper, the mechanical properties of Q355NH resistant steel welded joints are studied. Through the analysis of mechanical properties of welded joints, the results showed that the tensile strength of the welded joints decreased after annealing and the elongation increased. The impact test results of tensile specimens before and after annealing showed that the impact energy of the weld area increased greatly after annealing, while the impact energy of the heat affected zone changed little. Furtherly, fatigue strength of specimens before and after annealing was compared, and the results showed that under the condition of high cycle fatigue, the un-annealed specimens were broken and the fracture position was located on the parent metal, whereas the annealed specimens did not break.

scholarly journals Pengaruh Ketebalan Untuk White Cast Iron Low Chrome And Low Nikel Terhadap Kekerasan, Keausan, Serta Struktur Mikro Untuk Aplikasi Di Dalam Ball Grinding

2021 ◽  
Vol 1 (1) ◽  
pp. 12
Author(s):  
Uum Sumirat ◽  
Yusril Irwan ◽  
Hermawan S
Keyword(s):  
Cast Iron ◽  
Ball Mill ◽  
Test Specimen ◽  
Impact Test ◽  
Fine Particles ◽  
White Cast Iron ◽  
Hardness Test ◽  
Production Costs ◽  
Test Results ◽  
The Impact

Grinding Ball adalah salah satu komponen dalam mesin ball mill yang berfungsi untuk menggerus batuan mineral menjadi partikel yang sangat halus. Apabila grinding ball tersebut dapat dibuat di Indonesia, diharapkan harganya bisa lebih murah sehingga biaya produksi semen dapat diturunkan, harga semen lebih terjangkau, dan  kesejahteraan rakyat dapat ditingkatkan. Tujuan dari penelitian tugas akhir ini untuk mengembangkan prototype grinding ball pada ball mill sehingga dapat mensubtitusikan impor keluar negeri serta dapat memproduksi sendiri di dalam negeri dan bersaing dengan produk impor. Pengembangan prototype grinding ball pada ball mill menggunakan bahan material white cast iron dengan melalui proses pengecoran. Pengembangan ini bertujuan untuk mengetahui sifat material yang dalam hubunganya dengan sifat fisis dan mekanik melalui pengujian uji impak, kekerasan, serta struktur mikro. Hasil uji kekerasan menunjukan nilai kekerasan untuk spesimen uji keras 273,65 HB dan untuk spesimen uji impak 334,379 HB. Hasil uji impak menunjukan Harga impak 2,64 J/mm².  Kata Kunci : grinding ball, ball mill, white cast iron. ABSTRACT Grinding Ball is one of the components in a ball mill machine that functions to grind mineral rock into very fine particles. If the grinding ball can be made in Indonesia, it is hoped that the price will be cheaper so that cement production costs can be lowered, cement prices are more affordable, and people's welfare can be increased. The purpose of this final project research is to develop a prototype grinding ball in a ball mill so that it can substitute foreign imports and can produce domestically and compete with imported products. The development of the grinding ball prototype in the ball mill uses white cast iron material through a casting process. This development aims to determine the properties of the material in relation to physical and mechanical properties through impact, hardness, and microstructure tests. The hardness test results showed the hardness value for the hard test specimen 273,65 HB and for the impact test specimen 334,379 HB. The impact test results show the impact price is 2,64 J/mm². Keyword : grinding ball, ball mill, white cast iron

scholarly journals Impact resistance of steel materials to ballistic ejecta and shelter development using steel deck plates

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Hiroyuki Yamada ◽  
Kohei Tateyama ◽  
Shino Naruke ◽  
Hisashi Sasaki ◽  
Shinichi Torigata ◽  
...  
Keyword(s):  
Impact Energy ◽  
Impact Test ◽  
Impact Resistance ◽  
Protective Layer ◽  
High Strength ◽  
Steel Plates ◽  
Corrugated Plates ◽  
Shelter Construction ◽  
The Impact ◽  
Ballistic Ejecta

AbstractThe destruction caused by ballistic ejecta from the phreatic eruptions of Mt. Ontake in 2014 and Mt. Kusatsu-Shirane (Mt. Moto-Shirane) in 2018 in Japan, which resulted in numerous casualties, highlighted the need for better evacuation facilities. In response, some mountain huts were reinforced with aramid fabric to convert them into shelters. However, a number of decisions must be made when working to increase the number of shelters, which depend on the location where they are to be built. In this study, we propose a method of using high-strength steel to reinforce wooden buildings for use as shelters. More specifically, assuming that ballistic ejecta has an impact energy of 9 kJ or more, as in previous studies, we developed a method that utilizes SUS304 and SS400 unprocessed steel plates based on existing impact test data. We found that SUS304 is particularly suitable for use as a reinforcing material because it has excellent impact energy absorption characteristics due to its high ductility as well as excellent corrosion resistance. With the aim of increasing the structural strength of steel shelters, we also conducted an impact test on a shelter fabricated from SS400 deck plates (i.e., steel with improved flexural strength provided by work-hardened trapezoidal corrugated plates). The results show that the shelter could withstand impact with an energy of 13.5 kJ (2.66 kg of simulated ballistic ejecta at 101 m/s on impact). In addition, from the result of the impact test using the roof-simulating structure, it was confirmed the impact absorption energy is further increased when artificial pumice as an additional protective layer is installed on this structure. Observations of the shelter after the impact test show that there is still some allowance for deformation caused by projectile impact, which means that the proposed steel shelter holds promise, not only structurally, but also from the aspects of transportation and assembly. Hence, the usefulness of shelters that use steel was shown experimentally. However, shelter construction should be suitable for the target environment.

The Investigation in the Influence of Hardness to Transition Point after Tempering for Boric Carbon Steels

2013 ◽  
Vol 690-693 ◽  
pp. 186-192
Author(s):  
Ho Hua Chung ◽  
Tsong Hsin Chen
Keyword(s):  
Impact Energy ◽  
Carbon Steels ◽  
Material Strength ◽  
Tempering Temperature ◽  
Material Test ◽  
Wire Material ◽  
Steel Material ◽  
The Wire ◽  
The Impact ◽  
Test Fragment

This study concerned the influence of the material strength, ductility and impact energy and the relationship of the broken section profile vs. ductile transition brittle where the steel material was treated under different tempering temperature and hardness. Generally after the steel materials, 10B35 coil wire materials which was generally applied to form screws, was treated by quenching and tempering, its hardness ranged from HRC30 to HRC45. The results showed that the elongation rate beyond 20.4% would be proportional to the impact energy with linear relation, but with reverse proportion to the hardness value. The brittle-tough point of the hardness was set around HRC37 after heat treatment in order to balance the strength and the toughness. In addition, the coil wire materials were analyzed from broken section materials showing good toughness; this represented that the area of the cross section radiation layer due to ductile fracture would largely increase. On the contrary, the wire material test fragment with bad toughness represented that the area of the shear layer due to brittle fracture would largely increase as well. As to that material, if its hardness was greater than or equal to HRC37, that material would have an excellent turning danger from transition. At the same time, when the tempering temperature of the wire steel material was set under 4600C and its corresponding central hardness was about HRC37, the distance between two cementite phase layers suddenly increased. This result leaded to the reason why the wire material test fragment was turned into brittleness from ductility. Therefore, when the fastener was manufactured under tempering treatment, avoiding the tempering brittleness temperature range was necessary.

scholarly journals The Effect of Layers and Bullet Type on Impact Properties of Glass Fibre Reinforced Polymer (GFRP) Using a Single Stage Gas Gun (SSGG)

2014 ◽  
Vol 564 ◽  
pp. 428-433 ◽  
Author(s):  
S.N.A. Safri ◽  
Mohamed Thariq Hameed Sultan ◽  
N. Razali ◽  
Shahnor Basri ◽  
Noorfaizal Yidris ◽  
...  
Keyword(s):  
Impact Energy ◽  
Glass Fibre ◽  
Impact Test ◽  
Single Stage ◽  
Gas Gun ◽  
Reinforced Polymer ◽  
Glass Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced ◽  
The Impact

The purpose of this work is to study the best number of layer with the higher impact energy using Glass Fibre Reinforced Polymer (GFRP). The number of layers used in this study was 25, 33, 41, and 49. The impact test was performed using Single Stage Gas Gun (SSGG) for each layers given above with different bullets such as blunt, hemispherical and conical bullets. The gas gun pressure was set to 5, 10, 15 and 20 bar. All of the signals captured from the impact test were recorded using a ballistic data acquisition system. The correlation between the impact energy in terms of number of layer and type of bullet from this test are presented and discussed. It can be summarise that as the number of layer increases, impact energy also increases. In addition, from the results, it was observed that by using different types of bullets (blunt, hemispherical, conical), there is only a slight difference in values of energy absorbed by the specimen.

Analysis Method for Impact and Dispersion Behavior of Water-Filled Tank

2018 ◽  
Vol 4 (4) ◽  
Author(s):  
Hidekazu Takazawa ◽  
Kazuma Hirosaka ◽  
Katsumasa Miyazaki ◽  
Norihide Tohyama ◽  
Naomi Matsumoto
Keyword(s):  
Structural Damage ◽  
Impact Test ◽  
Velocity Ratio ◽  
Research Centre ◽  
Dispersion Pattern ◽  
Test Results ◽  
Analysis Method ◽  
Cylindrical Tank ◽  
Dispersion Behavior ◽  
The Impact

A new Japanese nuclear regulation involves estimating the possible damage to plant structures due to intentional aircraft impact. The effect of aircraft impact needs to be considered in the existing nuclear power plants. The structural damage and fuel dispersion behavior after aircraft impact into plant structures can be evaluated using finite element analysis (FEA). FEA needs validated experimental data to determine the reliability of the results. In this study, an analysis method was validated using a simple model such as a cylindrical tank. Numerical simulations were conducted to evaluate the impact and dispersion behavior of a water-filled cylindrical tank. The simulated results were compared with the test results of the VTT Technical Research Centre of Finland (VTT). The simulations were carried out using a multipurpose FEA code LS-DYNA®. The cylindrical tank was modeled using a shell element, and the tank water was modeled using smoothed particle hydrodynamics (SPH) elements. First, two analysis models were used to evaluate the effect of the number of SPH elements. One had about 300,000 SPH elements and the other had 37,000 SPH elements. The cylindrical tank ruptured in the longitudinal direction after crashing into a rigid wall, and the filled water dispersed. There were few differences in the simulated results when using different numbers of SPH elements. The VTT impact test was simulated with an arbitrary Lagrangian-Eulerian (ALE) element to consider the air drag. The analytical dispersion pattern and history of dispersion velocity ratio agreed well with the impact test results.

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

Sign in / Sign up

Export Citation Format

Share Document