Formation of α-Widmanstätten structure: effects of grain size and cooling rate on the Widmanstätten morphologies and on the mechanical properties in Ti6Al4V alloy

2001 ◽  
Vol 329 (1-2) ◽  
pp. 142-152 ◽  
Author(s):  
F.J. Gil ◽  
M.P. Ginebra ◽  
J.M. Manero ◽  
J.A. Planell
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Cooling Rate ◽  
Ti6al4v Alloy

Grain refinement of C-Mn steel through thermo-mechanical processing

2015 ◽  
Vol 13 (2) ◽  
pp. 282-297
Author(s):  
Archana Rethinam ◽  
Vinoo D. Shivakumar ◽  
L. Harish ◽  
M.B. Abhishek ◽  
G.V. Ramana ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Strain Rate ◽  
Cooling Rate ◽  
Hot Rolling ◽  
New Technologies ◽  
Processing Parameter ◽  
Coiling Temperature ◽  
Content Type ◽  
Plant Processing

Purpose – The application of new technologies requires, however, modern rolling mills. Indeed, in manufacturing plants of older types, strict compliance with the developed rolling regimes is not always feasible. Improving the mechanical properties in such cases is possible only by means of cooling. Compressive deformation behavior of carbon–manganese (C-Mn) grade has been investigated at temperatures ranging from 800-900°C and strain rate from 0.01-50 s−1 on Gleeble-3800, a thermo-mechanical simulator. Simulation studies have been conducted mainly to observe the microstructural changes for various strain rate and deformation temperatures at a constant strain of 0.5 and a cooling rate of 20°C s−1. Design/methodology/approach – The project begins with simulation of a hot rolling condition using the thermo-mechanical simulator; this was followed by microstructural examination and identification of phases present by using an optical microscope for hot-rolled coil and simulated samples; grain size measurement and size distribution studies; and optimization of finishing temperature, coiling temperature and cooling rate by mimicking plant processing parameters to improve the mechanical properties. Findings – As the strain rate and temperature increase, pearlite banding decreases gradually and finally gets completely eliminated, thereby improving the mechanical properties. True stress–strain curves were plotted to extrapolate the effect of strain-hardening and strain rate sensitivity on austenite (γ) and austenite–ferrite (γ-a) regions. To validate the effect of strain rate and temperature over the grain size, the hardness of simulated samples was measured using the universal hardness tester and the corresponding tensile strength was found from the standard hardness chart. Practical implications – The results of the study carried out have projected a new technology of thermo-mechanical simulation for the studied C-Mn grade. These results were used to optimize the plant processing parameter like finishing and coiling temperature and finishing stands strain rate. Originality/value – By controlling the hot rolling conditions like finishing, coiling temperature and cooling rate, structures differing in mechanical properties can be obtained for the same material. Accurate understanding of a structure being formed when different temperatures are applied enables the control of the process that assures intended structures and mechanical properties are achieved.

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

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.

Effects of Thermo-Mechanical Process on the Microstructure and Mechanical Properties of Low Carbon HSLA Steels

2006 ◽  
Vol 15-17 ◽  
pp. 786-791 ◽  
Author(s):  
J.S. Kang ◽  
Y. Huang ◽  
C.W. Lee ◽  
Chan Gyung Park
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Cooling Rate ◽  
High Strength ◽  
Nucleation Site ◽  
Polygonal Ferrite ◽  
Low Alloy Steels ◽  
Low Carbon ◽  
Microstructure And Mechanical Properties ◽  
Average Grain Size

Effects of deformation at austenite region and cooling rate on the microstructure and mechanical properties of low carbon (0.06 wt. % C) high strength low alloy steels have been investigated. Average grain size decreased and polygonal ferrite transformation promoted with increasing deformation amount at austenite region due to increase of ferrite nucleation site. Microstructure was also influenced by cooling rate resulting in the development of a mixture of fine polygonal ferrite and acicular ferrite at 10°C/s cooling rate. Discontinuous yielding occurred in highly deformed specimen due to the formation of polygonal ferrite. However, small grain size of highly deformed specimen caused lower ductile-to-brittle transition temperature than slightly deformed specimen.

Effect of Cooling Speed on the Microstructure and Mechanical Properties of Sn-0.7Cu-0.05Ni Solder Alloy

2018 ◽  
Vol 934 ◽  
pp. 73-78
Author(s):  
Phairote Sungkhaphaitoon
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Melting Point ◽  
Cooling Rate ◽  
Solder Alloy ◽  
Testing Machine ◽  
Solder Alloys ◽  
Scanning Calorimetry ◽  
Microstructure And Mechanical Properties ◽  
Cooling Speed

To study the effect of cooling speed on the microstructure and mechanical properties of Sn-0.7Cu-0.05Ni solder alloy, molten alloys were cooled at two different rates, using water-cooling and mold-cooling. The mechanical properties of the obtained alloys were analyzed with a universal testing machine (UTM) and by Vickers microhardness testing (HV). The microstructures were characterized using an optical microscope (OM) and energy dispersive X-ray spectroscopy (EDX).The melting point was ascertained by differential scanning calorimetry (DSC). The cooling rate of the water-cooled system (0.28 o C/s) was faster than the cooling rate of the mold-cooled system (0.05 °C/s). The grain size of the alloy produced by the faster cooling rate was finer than that of the alloy obtained from the slower cooling rate. This finer grain size gave the alloy superior ultimate tensile strength (UTS) and hardness but inferior ductility (%EL). The microstructure of both Sn-0.7Cu-0.05Ni solder alloys exhibited three phases of β-Sn, Cu6Sn5 and (Cu,Ni)6Sn5 intermetallic compounds. The melting point and undercooling of the solder alloys was 233.8 °C and 35.7 °C, respectively.

Effect of Cooling Rate on Microstructure of Rejuvenated Fe-Ni Based Superalloys

2020 ◽  
Vol 856 ◽  
pp. 76-84
Author(s):  
Kittawat Srimark ◽  
Panyawat Wangyao ◽  
Tanaporn Rojhirunsakool
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
High Temperature ◽  
Cooling Rate ◽  
Volume Fraction ◽  
Air Cooling ◽  
Gamma Prime ◽  
Microstructural Instability ◽  
Cooling Air

Fe-Ni based superalloys have been widely used in land-base gas turbine application. The turbine blade was in service for 50,000 h at high temperature and stresses. When subjected to long-term exposure at high temperature, the microstructure lost its best mechanical properties due to the microstructural instability. The aim of this research is to understand the effect of cooling rate on gamma (γ) grain size and gamma prime (γ’) particle size, morphology, and its volume fraction in rejuvenated Fe-Ni based superalloys. The alloys were solutionized above the γ’ solvus temperature at 1125 °C for 2 h for homogenization and cooling to room temperature at different cooling rates. The alloys were experienced with furnace cooling, air cooling, oil quenching, and water quenching. Microstructural analyses were investigated. Grain size, morphology, volume fraction of γ’ precipitates were investigated. Preliminary mechanical properties such as microhardness was conducted.

Effect of original grain size on microstructure and properties of extruded Mg-2Zn-0.2Mn biomedical alloy

2019 ◽  
Vol 201 (1) ◽  
pp. 231-240
Author(s):  
Zhou shijie ◽  
Liu hengquan ◽  
Huang nan
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Magnesium Alloy ◽  
Cooling Rate ◽  
Processing Condition ◽  
Mg Alloy ◽  
Cast Ingot ◽  
Dynamic Recrystallisation ◽  
Cast Magnesium ◽  
Degradation Properties

Magnesium is a biocompatible and biodegradable metal, which has attracted much interest in biomedical engineering. Cast magnesium alloy shows the low strength and plasticity at ambient temperature. Microstructure, mechanical properties and degradation properties of the extrusion pressed magnesium alloy have been investigated for biomedical application in detail by optical microscopes, mechanical properties testing and corrosion testing. The magnesium alloy ingots were gained by different cooling rate. Then the ingots were extrude into bar at the same processing condition. The results show that the cooling rate of cast ingot is important factors that affect the properties of Mg alloy by dynamic recrystallisation extruding. The cooling rate of cast ingot has been successfully applied to control the microstructure, mechanical and degradation properties of the Mg alloy. Optical microscopy observation has indicated that the grain size of the dynamic recrystallisation extruding has been significantly decreased from fast cooling cast magnesium ingot, which has mainly contributed to the high tensile strength and good elongation. Fasting cooling rate of cast ingot and dynamic recrystallisation extruding has provided moderate corrosion resistance, which has opened a new window for materials design, especially for biomedical.

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.

Effects of cooling rate on the mechanical properties of dual phase treated vanadium steels

1983 ◽  
Vol 41 ◽  
pp. 220-221
Author(s):  
L.J. Chen ◽  
H.C. Cheng ◽  
J.R. Gong ◽  
J.G. Yang
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
Automobile Industry ◽  
High Strength ◽  
Weight Percent ◽  
Low Alloy Steels ◽  
Dual Phase ◽  
Resource Requirement ◽  
Alloy Steels ◽  
Potential Weight

For fuel savings as well as energy and resource requirement, high strength low alloy steels (HSLA) are of particular interest to automobile industry because of the potential weight reduction which can be achieved by using thinner section of these steels to carry the same load and thus to improve the fuel mileage. Dual phase treatment has been utilized to obtain superior strength and ductility combinations compared to the HSLA of identical composition. Recently, cooling rate following heat treatment was found to be important to the tensile properties of the dual phase steels. In this paper, we report the results of the investigation of cooling rate on the microstructures and mechanical properties of several vanadium HSLA steels.The steels with composition (in weight percent) listed below were supplied by China Steel Corporation: 1. low V steel (0.11C, 0.65Si, 1.63Mn, 0.015P, 0.008S, 0.084Aℓ, 0.004V), 2. 0.059V steel (0.13C, 0.62S1, 1.59Mn, 0.012P, 0.008S, 0.065Aℓ, 0.059V), 3. 0.10V steel (0.11C, 0.58Si, 1.58Mn, 0.017P, 0.008S, 0.068Aℓ, 0.10V).

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