Effect of Quenching Temperature on Tensile Strength and Fatigue Behavior of an EA4T Steel

Author(s):  
Zhenghong Yao ◽  
Weibing Dai ◽  
Bing Cai ◽  
Changyou Li ◽  
Hongzhuang Zhang ◽  
...  
Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2171
Author(s):  
Armin Yousefi ◽  
Ahmad Serjouei ◽  
Reza Hedayati ◽  
Mahdi Bodaghi

In the present study, the fatigue behavior and tensile strength of A6061-T4 aluminum alloy, joined by friction stir spot welding (FSSW), are numerically investigated. The 3D finite element model (FEM) is used to analyze the FSSW joint by means of Abaqus software. The tensile strength is determined for FSSW joints with both a probe hole and a refilled probe hole. In order to calculate the fatigue life of FSSW joints, the hysteresis loop is first determined, and then the plastic strain amplitude is calculated. Finally, by using the Coffin-Manson equation, fatigue life is predicted. The results were verified against available experimental data from other literature, and a good agreement was observed between the FEM results and experimental data. The results showed that the joint’s tensile strength without a probe hole (refilled hole) is higher than the joint with a probe hole. Therefore, re-filling the probe hole is an effective method for structures jointed by FSSW subjected to a static load. The fatigue strength of the joint with a re-filled probe hole was nearly the same as the structure with a probe hole at low applied loads. Additionally, at a high applied load, the fatigue strength of joints with a refilled probe hole was slightly lower than the joint with a probe hole.


2012 ◽  
Vol 706-709 ◽  
pp. 2734-2739 ◽  
Author(s):  
Hana Jirková ◽  
Ludmila Kučerová ◽  
Bohuslav Mašek

The use of the combined influence of retained austenite and bainitic ferrite to improve strength and ductility has been known for many years from the treatment of multiphase steels. Recently, the very fine films of retained austenite along the martensitic laths have also become the centre of attention. This treatment is called the Q-P process (quenching and partitioning). In this experimental program the quenching temperature and the isothermal holding temperature for diffusion carbon distribution for three advanced high strength steels with carbon content of 0.43 % was examined. The alloying strategies have a different content of manganese and silicon, which leads to various martensite start and finish temperatures. The model treatment was carried out using a thermomechanical simulator. Tested regimes resulted in a tensile strength of over 2000MPa with a ductility of above 14 %. The increase of the partitioning temperature influenced the intensity of martensite tempering and caused the decrease of tensile strength by 400MPa down to 1600MPa and at the same time more than 10 % growth of ductility occurred, increasing it to more than 20%.


Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1023 ◽  
Author(s):  
Byung-Hoon Lee ◽  
Sung-Woo Park ◽  
Soong-Keun Hyun ◽  
In-Sik Cho ◽  
Kyung-Taek Kim

The effect of heat treatment condition on non-Cu AA7021 alloy was investigated with respect to mechanical properties and very high cycle fatigue behavior. With a focus on the influence of heat treatment, AA7021 alloy was solution heat-treated at 470 °C for 4 h and aged at 124 °C. Comparing the results of solution-treated and peak-aged AA7021 alloy shows a significant increase in Vickers hardness and tensile strength. The hardness of AA7021 alloy was increased by 65% after aging treatment, and both tensile strength and yield strength were increased by 50~80 MPa in each case. In particular, this paper investigated the very high cycle fatigue behavior of AA7021 alloy with the ultrasonic fatigue testing method using a resonance frequency of 20 kHz. The fatigue results showed that the stress amplitude of peak-aged AA7021 alloy was about 50 MPa higher than the solution-treated alloy at the same fatigue cycles. Furthermore, it was confirmed that the size of the crack initiation site was larger after peak aging than after solution treatment.


2020 ◽  
Vol 993 ◽  
pp. 492-496
Author(s):  
Peng Xiao Zhu ◽  
Yi Li ◽  
Bo Chen ◽  
Kun Feng

The effects of different zero-holding quenching temperatures on the tempering microstructure, mechanical properties and wear resistance of 40Cr were studied. The results showed that the microstructure of 40Cr was tempered sorbite and a small amount of unmelted ferrite after quenching at 850 °C and tempering at 550 °C for 2 h. Tempered sorbite was obtained after quenching at 880 °C~910 °C and tempering at 550 °C for 2 h. With the increasing of quenching temperature at zero holding temperature, the tensile strength and yield strength of 40Cr increased, while the elongation and impact toughness decreased. With the decreasing of impact test temperature, the ballistic work of 40Cr decreased gradually, and decreased fastest between 0 °C~-20 °C. 40Cr had the best impact performance after quenching at 850 °C and tempering at 550 °C for 2 h. 40Cr had the smallest wear loss after quenching at 880 °C and tempering at 550 °C for 2 h. Its wear marks were smooth, and had the shallowest furrows and ridges.


2015 ◽  
Vol 808 ◽  
pp. 28-33 ◽  
Author(s):  
Constantin Dulucheanu ◽  
Nicolai Bancescu ◽  
Traian Severin

In this article, the authors have analysed the influence of quenching temperature (TQ) on the mechanical properties of a dual-phase steel with 0.094 % C and 0.53% Mn. In order to obtain a ferrite-martensite structure, specimens of this material have been the subjected to intercritical quenching that consisted of heating at 750, 770, 790, 810 and 830 °C, maintaining for 30 minutes and cooling in water. These specimens have then been subjected to metallographic analysis and tensile test in order to determine the volume fraction of martensite (VM) in the structure, ultimate tensile strength (Rm), the 0.2% offset yield strength (Rp0.2), the total elongation (A5) and the Rp0.2/Rm ratio.


2018 ◽  
Vol 104 (2) ◽  
pp. 88-97 ◽  
Author(s):  
Takuro Ogawa ◽  
Motomichi Koyama ◽  
Yuri Nishikura ◽  
Kaneaki Tsuzaki ◽  
Hiroshi Noguchi

2011 ◽  
Vol 335-336 ◽  
pp. 577-582
Author(s):  
Xiao Wen Chen ◽  
De Fen Zhang ◽  
Guang Wen Long ◽  
Qin Zou ◽  
Li Wang

45 steel was quenched with zero time holding at different temperatures, followed by a high temperature tempering. The influence of quenching temperature on hardness, yield strength, tensile strength and microstructure of the steels was investigated by Rockwell tester, universal testing machines and metallographic microscopy, respectively. The results show that under quenching condition of zero time holding, hardness and strength of the 45 steel increase with increasing quenching temperature and reach the maximum at 860 °C, where the content of martensite is maximum while that of ferrite is minimum in the specimen. At higher temperatures, the grains become obviously coarse, resulting in decrease of mechanical properties.


2008 ◽  
Vol 385-387 ◽  
pp. 725-728 ◽  
Author(s):  
J.H. Cha ◽  
H.H. Cho ◽  
W.H. Kim ◽  
S.I. Kwun ◽  
Dong Hyuk Shin

The low cycle fatigue(LCF) test was performed to characterize the influences of the equal channel angular pressing(ECAP) and subsequent annealing of Al 5052 alloy. In the present research, one group of Al 5052 alloy specimens was directly subjected to ECAP, while another was subjected to ECAP and subsequent annealing. It was found that the tensile strength of the Al 5052 alloy increased, while its elongation decreased, with increasing number of ECAP passes. The LCF test was conducted at constant total strain amplitudes of 0.5%, 0.7%, 0.9% and 1.1%. Only cyclic hardening was observed as the number of fatigue cycles increased at all strain amplitudes in the specimen without ECAP. However, the ECAPed specimens showed a slight amount of cyclic hardening in the beginning and then saturation until fracture.


2012 ◽  
Vol 490-495 ◽  
pp. 3257-3261
Author(s):  
An Ming Li ◽  
Meng Juan Hu

Influence of sub-temperature quenching temperature on the tensile strength, hardness and toughness of 35CrMo steel was studied. The microstructure characteristics of this steel after sub-temperature quenching were analyzed. The results showed in the range of 780~810°C the strength and hardness of the 35CrMo steel sub-temperature quenched increased with quenching temperature increasing, reached the highest strength and hardness at 800°C quenching and then began to decrease, while its elongation decreased with the quenching temperature increasing. The duplex microstructure of martensite and ferrite was obtained by sub-temperature quenching of 35CrMo steel. With the quenching temperature increasing, the ferrite content decreased and the distribution of ferrite morphology was changed. A small amount of strip ferrite existed in lath martensite lamellar when quenching temperature was 800°C and the impact toughness of 35CrMo steel was better than that of conventional samples 850°C completely quenched.


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