Effects of Austenitizing Temperature and Cooling Rate on the Mechanical Properties of 36MnVS4 Steel for Automobile Engine Connecting Rod

2017 ◽  
Vol 898 ◽  
pp. 1195-1201 ◽  
Author(s):  
Jun Ru Li ◽  
Xiao Hang Sun ◽  
Yan Ji ◽  
Lie Chen ◽  
Guang Lei Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Cooling Rate ◽  
Connecting Rod ◽  
Austenitizing Temperature ◽  
Grain Sizes ◽  
Austenite Grain ◽  
Fracture Splitting ◽  
The Relationship ◽  
Prior Austenite Grain

The relationship between microstructure and mechanical properties of 36MnVS4 steel was studied. Different prior austenite grain sizes were obtained by austenitizing at 850, 950 and 1050 °C, respectively, and different ferrite contents were obtained by different cooling rates. Austenitizing temperature mainly influenced the grain size. With the austenitizing temperature increasing, grain size increased and the phase transformation starting temperature increased. Also, the strength increased and the plasticity and toughness decreased. Cooling rate mainly influenced the microstructure percentage. With the cooling rate increasing, ferrite percentage decreased and pearlite percentage increased. And meanwhile, the strength increased and ductility and toughness decreased. Microstructure had a significant influence on fracture splitting properties. With the grain size increasing, fracture splitting properties were markedly improved. With the ferrite percentage increasing and pearlite percentage decreasing, fracture splitting properties were worsened.

scholarly journals The Effect of Cooling Rate on Mechanical Properties of Carbon Steel (St 35)

2014 ◽  
Vol 7 (1) ◽  
pp. 109-118
Author(s):  
Jenan Mohammed Nagie
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Size ◽  
Carbon Steel ◽  
Cooling Rate ◽  
Experimental Results ◽  
Heat Treated ◽  
Before And After ◽  
Water Media ◽  
The Relationship

This paper is aimed to study the effect of cooling rate on mechanical properties of Steel 35. Specimens prepared to apply tensile, torsion, impact and hardness tests.Many prepared specimens heat treated at (850ºC) for one hour and subsequently were cooled by three different media [Water-Air-furnace] to show the effect of Medias cooling rate on mechanical properties. Microstructures of all specimens examined before and after heat treatment by an optical microscopy.To figure the phases obtained after heat treatment and its effect on the mechanical properties Experimental results have shown that the microstructure of steel can be changed and significantly improved by varying line cooling rate thus, improving one property will effect on the others because of the relationship between all properties.In water media tensile, torsion and hardness improved while impact results reduced. Air media contributed in improving most of the mechanical properties because of grain size homogeneity. At furnace media ductility and impact improved

scholarly journals Influence of Austenite Grain Size on Mechanical Properties after Quench and Partitioning Treatment of a 42SiCr Steel

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 577 ◽  
Author(s):  
Sebastian Härtel ◽  
Birgit Awiszus ◽  
Marcel Graf ◽  
Alexander Nitsche ◽  
Marcus Böhme ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Heating Rates ◽  
Austenite Grain Size ◽  
Grain Sizes ◽  
Austenite Grain ◽  
Martensitic Microstructure ◽  
Pre Treatment ◽  
Uneven Heating ◽  
Upsetting Test

This paper examines how the initial austenite grain size in quench and partitioning (Q-P) processes influences the final mechanical properties of Q-P steels. Differences in austenite grain size distribution may result, for example, from uneven heating rates of semi-finished products prior to a forging process. In order to quantify this influence, a carefully defined heat treatment of a cylindrical specimen made of the Q-P-capable 42SiCr steel was performed in a dilatometer. Different austenite grain sizes were adjusted by a pre-treatment before the actual Q-P process. The resulting mechanical properties were determined using the upsetting test and the corresponding microstructures were analyzed by scanning electron microscopy (SEM). These investigations show that a larger austenite grain size prior to Q-P processing leads to a slightly lower strength as well as to a coarser martensitic microstructure in the Q-P-treated material.

The effect of heat treatment on the mechanical properties of a low carbon steel (0.1%) for offshore structural application

2012 ◽  
Vol 226 (3) ◽  
pp. 242-251 ◽  
Author(s):  
Sung S Kang ◽  
Amir Bolouri ◽  
Chung-Gil Kang
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Size ◽  
Cooling Rate ◽  
Impact Energy ◽  
Cast Steel ◽  
Low Carbon ◽  
Austenite Grain Size ◽  
Tempering Temperature ◽  
Austenite Grain

In this study, a low carbon cast steel (0.1% C) alloy designed for offshore structures, and the mechanical properties of the alloy under different heat treatment cycles have been evaluated. The effect of austenitizing time on the austenite grain size was studied. Subsequently, the quenched samples with minimum austenite grain size subjected to tempering experiments at different tempering temperatures (450 °C, 550 °C, and 650 °C) and cooling rates (0.23, 36, and 50 °C/s) from the temperature. The results showed that by increasing the austenitizing time, the austenite grain size initially decreased and reached the minimum value with ASTM number of 6.35 and then followed by an increase. When the tempering temperature increased, yield and tensile strengths decreased, whereas the ductility properties improved. In addition, yield and tensile strengths were not affected by cooling rate from tempering temperature, whereas the ductility properties were slightly affected. The increase in tempering temperature significantly led to improvement in the toughness to fracture of the alloy. The effect of cooling rate on impact energy for the samples tempered at 450 °C and 550 °C was negligible. By the contrast, impact energy for the samples tempered at 650 °C was markedly affected by cooling rate, in which the highest value was achieved for a cooling rate of 50 °C/s.

The Effect of Austenitizing Temperature on Prior Austenite Grain Size in Martensitic Cast Steel

2013 ◽  
Vol 197 ◽  
pp. 53-57
Author(s):  
Grzegorz Golański ◽  
Cezary Kolan ◽  
Jerzy Kupczyk
Keyword(s):  
Grain Size ◽  
Prior Austenite ◽  
Cast Steel ◽  
Austenitizing Temperature ◽  
Austenite Grain Size ◽  
Austenite Grain ◽  
Cast Steels ◽  
Mean Diameter ◽  
The Mean ◽  
Prior Austenite Grain

The GX12CrMoVNbN9-1 (GP91) cast steel belongs to a new group of high-temperature creep resistant cast steels being introduced to the power industry. The cast steel is characterized by higher mechanical properties in comparison with the low alloy Cr – Mo or Cr – Mo – V cast steels used so far. The mechanical properties of martensitic cast steels depend on the parameters of heat treatment, such as the temperature of austenitizing. The paper is to present the results of research on the influence of austenitizing temperature ranging from 980 to 1100oC and hold time of 12 hours on the growth of austenite grain. The tests were carried out on test samples taken from a test coupon. Description of the influence of austenitizing temperature on the austenite grain size was made using the mean diameter of grain. Performed tests have shown that the distributions of mean diameters are of normal character, on the significance levels α = 0.05 and α = 0.04. For the investigated temperature range, the ν coefficient of non-homogeneity of the mean diameter of prior austenite grain was determined. The achieved results have proved that in the temperature range of 1010 to 1070°C the mean diameters stay within the same grade of grain size and the considerable grain growth is visible at the temperature of 1100°C.

scholarly journals Effect of As-Cast Structure and Macrosegregation on Mechanical Properties in Direct-Quenched Low-Alloy Ultrahigh-Strength Steel

2020 ◽  
Author(s):  
S. Koskenniska ◽  
A. Kaijalainen ◽  
T. Pikkarainen ◽  
S. Mehtonen ◽  
D. Porter ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Impact Toughness ◽  
Prior Austenite ◽  
Cast Structure ◽  
Ultrahigh Strength ◽  
Grain Sizes ◽  
Austenite Grain ◽  
Interdendritic Segregation ◽  
Hot Rolled ◽  
Prior Austenite Grain

Abstract The effect of as-cast structure and macrosegregation on the mechanical properties of a direct-quenched low-alloy martensitic ultrahigh-strength aluminum killed and calcium treated steel cast at different superheats was studied. Samples from the castings were laboratory hot rolled with two different finishing rolling temperatures to distinguish the effect of hot rolling. Using optical emission spectrometry, the steel composition was analyzed as a function of slab thickness in order to detect the variations in steel chemistry due to macrosegregation. Further, hardness profiles, prior austenite grain sizes and tensile and impact toughness were determined for the hot-rolled specimens. It was found that interdendritic segregation was more intense at the higher superheat, which led to more pronounced positive segregation in the columnar-to-equiaxed transition (CET) zone, and negative segregation between CET and the centerline. These macrosegregation patterns were inherited by the hot-rolled samples causing local variations in hardness, which followed the variations in carbon content. However, altering the superheat had a minor effect on the nominal transformed microstructures and nominal prior austenite grain sizes. This occurred because of the interdendritic segregation induced composition variations both enlarged and decreased by turns the grain sizes. The CET also reduced measured impact toughness values.

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