Microstructural characterization and investigation of slurry erosion performance of cyclically heat treated martensite steel

Author(s):  
Jai Singh ◽  
S.K. Nath

2015 ◽  
Vol 60 (2) ◽  
pp. 1331-1334 ◽  
Author(s):  
M.C. Oh ◽  
H. Yeom ◽  
Y. Jeon ◽  
B. Ahn

Abstract The influence of surface heat treatment using laser radiation on the fatigue strength and corresponding microstructural evolution of AISI 4140 alloy steel was investigated in this research. The AISI 4140 alloy steel was radiated by a diode laser to give surface temperatures in the range between 600 and 800°C, and subsequently underwent vibration peening. The fatigue behavior of surface-treated specimens was examined using a giga-cycle ultrasonic fatigue test, and it was compared with that of non-treated and only-peened specimens. Fatigue fractured surfaces and microstructural evolution with respect to the laser treatment temperatures were investigated using an optical microscope. Hardness distribution was measured using Vickers micro-hardness. Higher laser temperature resulted in higher fatigue strength, attributed to the phase transformation.



2020 ◽  
Vol 403 ◽  
pp. 103-109
Author(s):  
Jana Ptačinová ◽  
Juraj Ďurica ◽  
Matej Pašák ◽  
Martin Kusy ◽  
Peter Jurči

Microstructural characterization of ledeburitic tool steel Vanadis 6 after sub-zero treatment and tempering has been examined. The samples were heat treated using following schedules: heating to the austenitizing temperature (TA = 1050 °C) in a vacuum furnace, hold at the final temperature for 30 min. and nitrogen gas quenching (5 bar). The sub-zero treatments consisted of immediate (after quenching) immersion of the material into the liquid helium (-269 °C), hold at the soaking temperature and removal the samples to be heated to a room temperature. Double tempering has been performed at the temperatures from the range 170 – 530 °C, whereas each tempering cycle was realized with a hold of 2 h. Typical heat treated microstructure of ledeburitic steels consists, besides of the martensitic matrix with certain amount of retained austenite, of several types of carbides – eutectic, secondary and small globular carbides. In sub-zero treated steel the amount of retained austenite is significantly reduced. The population density of small globular carbides increase as a result of sub-zero treating. Tempering of the material resulted in decrease in population density of small globular carbides with increasing the tempering temperature. The hardness of sub-zero treated material is higher than that of conventionally quenched one. Also, this tendency is preserved when the steel is low-temperature tempered. On the other hand, the hardness of conventionally quenched steel becomes higher than that of SZT one when tempered at the temperature of secondary hardening.



Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 862 ◽  
Author(s):  
Maribel Arribas ◽  
Teresa Gutiérrez ◽  
Eider Del Molino ◽  
Artem Arlazarov ◽  
Irene De Diego-Calderón ◽  
...  

In this work, four low carbon steels with different contents of Mn and Ni were heat treated by quenching and partitioning (Q&P) cycles where high partitioning temperatures, in the range of 550 °C–650 °C, were applied. In order to elucidate the effect of applying these high partitioning temperatures with respect to more common Q&P cycles, the materials were also heat treated considering a partitioning temperature of 400 °C. The microstructure evolution during the Q&P cycles was studied by means of dilatometry tests. The microstructural characterization of the treated materials revealed that austenite retention strongly depended on the alloy content and partitioning conditions. It was shown that the occurrence of austenite reverse transformation (ART) in the partitioning stage in some of the alloys and conditions was a very effective mechanism to increase the austenite content in the final microstructure. However, the enhancement of tensile properties achieved by the application of high partitioning temperature cycles was not significant.



Author(s):  
C. Triveño Rios ◽  
S.F. Santos ◽  
Walter José Botta Filho ◽  
Claudemiro Bolfarini ◽  
Claudio Shyinti Kiminami


2020 ◽  
Vol 142 (5) ◽  
Author(s):  
M. Minhaj ◽  
Bhupinder Singh ◽  
Sunny Zafar

Abstract A composite clad of Ni-based alloy and B4C was developed on austenitic steel substrate through microwave hybrid heating. The B4C was added with Ni-based alloy powder in various weight proportions (0%, 5%, 10%, and 20%). The clads were investigated for the microstructural details, nanohardness and slurry erosion performance. Silt collected from river Uhl was used as the erodent for the slurry erosion test. Slurry erosion performance of the clads was evaluated at an impact angle of 90 deg and jet velocity of 40 m/s. Microstructural characterization confirms the uniform distribution of hard (boride and carbide) phases in the Ni-based matrix of the microwave composite clads. The presence of hard phases in the Ni-based matrix enhanced the slurry erosion resistance performance.



2014 ◽  
Vol 783-786 ◽  
pp. 228-233 ◽  
Author(s):  
Lorella Ceschini ◽  
A. Jarfors ◽  
A. Morri ◽  
A. Morri ◽  
F. Rotundo ◽  
...  

The aim of the present study was to characterize the high temperature tensile behaviour of the C355 (Al-Si-Cu-Mg) alloy produced under controlled casting condition so as to obtain different secondary dendrite arm spacing (SDAS). C355 samples were produced through a gradient solidification equipment able to produce microstructures with fine (20-25 μm) and coarse (50-70 μm) SDAS values. The as-produced specimens were subjected to hot-isostatic pressing and then T6 heat treated. Microstructural characterization, room and high temperature (200 °C) tensile tests were carried out on the heat treated specimens. The tensile behaviour was related to the different SDAS value of the samples.



2012 ◽  
Vol 710 ◽  
pp. 500-505 ◽  
Author(s):  
Hassan Jayaraj Amarendra ◽  
Pradeep Kalhan ◽  
Gajanan Prabhakar Chaudhari ◽  
Sameer Kumar Nath ◽  
Shravan Kumar

In the present work, effect of various heat treatments on slurry erosion behavior of 13Cr-4Ni martensitic stainless steel (MSS) at different impingement angles has been studied. The as-received cast bars of MSS were given various heat treatments. These heat treatments involved the austenitization of cast steel at temperatures of 950° C, 1000° C and 1050° C for different soaking durations of 2, 4 and 6 h at each temperature. This was followed by oil quenching then tempering for 1 h at a 600° C air cooled. Heat treated MSS samples were characterized for microstructure and mechanical properties viz. hardness, ductility (% elongation), tensile strength (UTS), and toughness. For wear characterization, slurry erosion tests were conducted at different impingement angles for as-received cast and heat treated samples. The heat treated MSS shows approximately 34% lesser weight loss as compared to as-received cast MSS. Increase in toughness of heat treated samples is found to be responsible for the improved slurry erosion resistance. Impingement angle close to 0° showed least wear loss.



Author(s):  
J. A. Sutliff ◽  
B. P. Bewlay

In-situ composite Nb-Si alloys have been studied by several investigators as potential high temperature structural materials. The two major processing routes used to fabricate these composites are directional solidification and extrusion of arc-cast solidified ingots. In both cases a stable microstructure of primary Nb dendrites in a eutectoid of Nb and Nb5Si3 phases is developed after heat treatment. The Nb5Si3 phase is stable at room temperature and forms as a decomposition product of the high temperature Nb3Si phase. The anisotropic microstructures developed by both directional solidification and extrusion require evaluation of the texture to fully interpret the fracture and other orientation dependent mechanical behavior of these composites.In this paper we report on the microstructural characterization of a directionally solidified (DS) and heat treated Nb-16 at.%Si alloy. The microtexture of each of the phases (Nb, Nb5Si3) was determined using the Electron BackScattering Pattern (EBSP) technique for electron diffraction in the scanning electron microscope. A system employing automatic diffraction pattern recognition, crystallographic analysis, and sample or beam scanning was used to acquire the microtexture data.



2008 ◽  
Vol 59 (12) ◽  
pp. 1753-1757 ◽  
Author(s):  
Gisele Ferreira de Lima ◽  
Alex Matos da Silva Costa ◽  
Paulo Atsushi Suzuki ◽  
Carlos Ângelo Nunes ◽  
Gilberto Carvalho Coelho


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