Effect of impurities on intercrystalline fracture of steel 18Kh2N4VA after quenching and tempering

1980 ◽  
Vol 12 (2) ◽  
pp. 241-245
Author(s):  
G. A. Filippov ◽  
V. N. Marchenko ◽  
D. A. Litvinenko ◽  
V. I. Sarrak ◽  
O. N. Chevskaya
2018 ◽  
Vol 18 (1) ◽  
pp. 125-135
Author(s):  
Sattar H A Alfatlawi

One of ways to improve properties of materials without changing the product shape toobtain the desired engineering applications is heating and cooling under effect of controlledsequence of heat treatment. The main aim of this study was to investigate the effect ofheating and cooling on the surface roughness, microstructure and some selected propertiessuch as the hardness and impact strength of Medium Carbon Steel which treated at differenttypes of heat treatment processes. Heat treatment achieved in this work was respectively,heating, quenching and tempering. The specimens were heated to 850°C and left for 45minutes inside the furnace as a holding time at that temperature, then quenching process wasperformed in four types of quenching media (still air, cold water (2°C), oil and polymersolution), respectively. Thereafter, the samples were tempered at 200°C, 400°C, and 600°Cwith one hour as a soaking time for each temperature, then were all cooled by still air. Whenthe heat treatment process was completed, the surface roughness, hardness, impact strengthand microstructure tests were performed. The results showed a change and clearimprovement of surface roughness, mechanical properties and microstructure afterquenching was achieved, as well as the change that took place due to the increasingtoughness and ductility by reducing of brittleness of samples.


2018 ◽  
Vol 60 (6) ◽  
pp. 614-618 ◽  
Author(s):  
Can Civi ◽  
Metin Yurddaskal ◽  
Enver Atik ◽  
Erdal Celik

2017 ◽  
Vol 907 ◽  
pp. 214-219 ◽  
Author(s):  
Dragoș Cristian Achiței ◽  
Petrică Vizureanu ◽  
Mirabela Georgiana Minciună ◽  
Mustafa Al Bakri Abdullah Mohd ◽  
Andrei Victor Sandu

The titanium alloys are used in aeronautical applications (up to 75% of titanium alloys), reinforcements, biomedical applications, army industry, because of a high traction resistance, low weight, excellent corrosion resistance and capacity to resist at extreme temperatures. However, some titanium applications are restricted by the small hardness, high friction coefficient and low usage resistance. The paper shows the experimental researches made on Ti-6Al-4V alloy, subjected to quenching and tempering heat treatments. The hardening heat treatment of titanium alloys with α+β structure consists in stabilization phenomenon of β solid solution dissolved in α’ and α’’ metastable phase. After quenching and tempering heat treatments, are obtained good mechanical properties in biphasic alloys, maintaining the plasticity characteristics in reasonable limits. The efficiency evaluation of heat treatments was realized through micro-hardness measurement and structure analyses on electronic microscope.


2015 ◽  
Vol 817 ◽  
pp. 115-120 ◽  
Author(s):  
Dan Zhang ◽  
Le Yu Zhou ◽  
Chao Lei Zhang ◽  
Chao Huang ◽  
Min Zhao ◽  
...  

Network carbide inheritance during heat treatment process of large shield machine bearing steel GCr15SiMn was investigated by heat treatment experiments and quantitative metallographic. Samples with the proeutectoid cementite network thickness in the range of 0.19~0.54 μm were obtained by changing austenitizing temperature and soaking time of pearlite transformation. The results show that the network in hot rolled bar can be improved when the pre-heat treatment temperature is 950 °C. When the network thickness is above 0.40 μm, the undissolved cementite networks present in microstructures after quenching and tempering. In a Chinese standard, the network grades are 1.5 and 3.0 degree when the networks thickness are 0.40 μm and 0.54 μm, respectively. The critical network thickness that can be eliminated by heat treatment is 0.29 μm.


1996 ◽  
Vol 35 (1) ◽  
pp. 93-100
Author(s):  
N. C. Birla ◽  
K. Gültekin ◽  
O. Addemir ◽  
A. Tekin

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