Effects of Quenching Temperature and Cooling Rate on the Microstructure and Mechanical Properties of U75V Rail Steel

2019 ◽  
Vol 8 (2) ◽  
pp. 249-255 ◽  
Author(s):  
Yuzhe Lan ◽  
Gang Zhao ◽  
Yaowen Xu ◽  
Chuanlong Ye ◽  
Shaocheng Zhang
Metals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 742 ◽  
Author(s):  
Khan ◽  
Yu ◽  
Wang ◽  
Jiang

The effect of cooling rate, ranging from 6 to 1 °C/s, on microstructure and mechanical properties in the coarse-grained heat affected zone (CGHAZ) of electroslag welded pearlitic rail steel has been investigated by using confocal scanning laser microcopy (CSLM) and Gleeble 3500 thermo-mechanical simulator. During heating, the formed austenite was inhomogeneous with fractions of untransformed ferrite, which has influenced the pearlite transformation during cooling by providing additional nucleation sites to pearlite. During cooling, at 6 °C/s, the microstructure was composed of martensite and bainite with little pearlite. From 4 to 1 °C/s, microstructures were completely pearlite. Lowering the cooling rate of the CGHAZ from 4 to 1 °C/s increased the pearlite start temperature and reduced the pearlite growth rate. Meanwhile, this increase in pearlite start temperature enlarged the pearlite interlamellar spacing. Alternatively, increasing pearlite interlamellar spacing in the CGHAZ by lowering the cooling rate from 6 to 1 °C/s reduced the hardness and tensile strength, whereas toughness was found unaffected by the pearlite interlamellar spacing. It has been found that a cooling rate of 4 °C/s leads to the formation of pearlite with fine interlamellar spacing of 117 nm in the CGHAZ of electroslag welded pearlitic rail steel where hardness is 425 HV, tensile strength is 1077 MPa, and toughness is 9.1 J.


2012 ◽  
Vol 52 (12) ◽  
pp. 2210-2219 ◽  
Author(s):  
Qiang Liu ◽  
Hongwei Zhang ◽  
Qiang Wang ◽  
Xiangkui Zhou ◽  
P^|^auml;r G. J^|^ouml;nsson ◽  
...  

2012 ◽  
Vol 182-183 ◽  
pp. 162-166
Author(s):  
Can Can Li ◽  
Hao Ran Geng ◽  
Zhen Yuan Li ◽  
Hai Ou Qin

In this paper, Al-12.6%Si/Al63Cu25Fe12 composites were fabricated by method of casting. The microstructure and chemical composition of Al63Cu25Fe12 quasicrystal alloy and Al-12.6%Si alloy reinforced by the quasicrystal were studied, and the mechanical properties of Al-12.6%Si composite were also measured. The results show that almost single quasicrystalline phases exist in the samples which are cast with the 1300°C melt. Quickly enough cooling rate and appropriate melt temperature are necessary for the formation of the quasicrystalline phase. In addition, Al-12.6%Si composite has optimal mechanical properties when the amount of Al63Cu25Fe12 quasicrystal is 3 wt%.


Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1238
Author(s):  
Jun Han ◽  
Tianliang Fu ◽  
Zhaodong Wang ◽  
Guodong Wang

In this paper, a 300 mm thickness ultra-heavy steel plate was selected as the research object. In addition, special roller quenching equipment and a new testing method were used to measure the quenching temperature curve at different positions of the steel plate. The relationships and corresponding interaction mechanisms between cooling rate, microstructure, and mechanical properties of an ultra-heavy steel plate during roller quenching were investigated. The results indicated that the cooling rate, strength, hardness, and impact energy decreased gradually along the thickness direction of the plate, while the cooling rate, average grain size, and mechanical properties were relatively uniform with little change along the length direction of the plate. The experimental results provide an effective way to further control the microstructure and properties of ultra-heavy steel plates during roller quenching.


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