Effect of Hot Rolling Process Parameters on Microstructure Transformation and Microstructure of 45MnSiV Steel

2019 ◽  
Vol 944 ◽  
pp. 265-271
Author(s):  
Yun Long Wang ◽  
Yin Li Chen ◽  
He Wei ◽  
Yi Na Zhao ◽  
Ze Sheng Liu
Keyword(s):  
Phase Transition ◽  
Cooling Rate ◽  
Transformation Temperature ◽  
Martensite Phase ◽  
Rolling Temperature ◽  
Layer Spacing ◽  
Final Rolling Temperature ◽  
Test Steel ◽  
Temperature Ranges ◽  
Final Rolling

The effects of final rolling temperature, cooling rate and deformation on phase transition point, the duration of the phase transition and the pearlite laminar layer of non-quenched and tempered steel 45MnSiV were studied by simulating the process of rolling and post-rolling cooling on Gleeble-3500 thermal simulator and thermal expansion tester. The results show that: the ferrite and pearlite transformation temperature ranges from 510 °C to 700 °C, and the bainite transformation temperature ranges from 400 °C to 500 °C when the steel is continuously cooled at a final rolling temperature of 950 °C, and the martensite transforming temperature is 300 °C under high cooling rate (> 10 °C/s); The pearlite laminar spacing decreases with the decrease of final rolling temperature. It can be seen that the rolling deformation increases the temperature at which the test steel undergoes a phase change at each cooling rate by comparing the results of deformation and no-deformation test at 950 °C. The effect of time advance on the phase transition zone of ferrite and pearlite is particularly obvious, but the effect on the phase transition temperature and time of the bainite and martensite phase transition is not obvious. When the final rolling temperature remains constant, the Rockwell hardness value of the test steel gradually increases, and the pearlite layer spacing decreases with the decrease of ferrite transformation temperature gradually and the increase of the cooling rate.

Improvement of Mechanical Properties and Corrosion Resistance by Deformation Induced Precipitation in Al-Zn-Mg-Cu Alloy

2017 ◽  
Vol 898 ◽  
pp. 179-190 ◽  
Author(s):  
Jin Rong Zuo ◽  
Long Gang Hou ◽  
Jin Tao Shi ◽  
Hua Cui ◽  
Lin Zhong Zhuang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Thermomechanical Treatment ◽  
High Strength ◽  
Alloy Sheet ◽  
Rolling Temperature ◽  
Al Alloy ◽  
Deformation Degree ◽  
Dynamic Aging ◽  
Final Rolling Temperature ◽  
Final Rolling

A final thermomechanical treatment (FTMT) including peak aging and subsequent dynamic aging was proposed to prepare 7055 Al alloy sheets. The optimization was based on nine well-planned orthogonal experiments. Three main processing conditions in the thermomechanical treatment for obtaining the optimum synthetic properties of 7055 (i.e. preheating temperature, final rolling temperature and deformation degree) were investigated. It was shown that the final rolling temperature is the most important factor among the three parameters, and the optimum properties (yield strength: 651 MPa, ultimate tensile strength: 660 MPa) of 7055 Al alloy sheet can be gained with preheating at 140oC and 40% deformation at 170oC. With dynamic aging, grain boundary precipitates became discontinuous without much coarsening of matrix precipitates, while they were continuously distributed after T6 aging. The present optimal FTMT process can improve the intergranular / exfoliation corrosion resistance without sacrificing the strength compared to T6 tempering. The present FTMT process as a good alternative can produce high-strength Al alloy sheets with high strength and good corrosion resistance efficiently and economically.

Experimental Investigation on Determinant of Steel Specimen Transformation Temperature under Air Cooling Conditions

2010 ◽  
Vol 148-149 ◽  
pp. 223-226
Author(s):  
Lian Sheng Chen ◽  
Tao Wang ◽  
Jin Ying Song ◽  
Yi Liu ◽  
Zhen Yu Liu ◽  
...  
Keyword(s):  
Phase Transition ◽  
Experimental Investigation ◽  
Transition Temperature ◽  
Cooling Rate ◽  
Phase Transition Temperature ◽  
Transformation Temperature ◽  
Steel Specimen ◽  
Air Cooling ◽  
Cooling Conditions ◽  
Metal Phase Transition

In order to get rid of thermal interferences, the experiment was conducted to test the temperature drops of 40Cr by embedding thermocouple in central part of the steel specimen under the air cooling conditions. The cooling rate of the center was obtained and the phase transition temperature at the start and end points were determined. By comparing with 40Cr CCT curves, obvious effects of the metal phase transition latent heat on cooling rate were shown. The results should be revised when CCT curves which obtained form constant-speed cooling rate conditions were used to determined phase transition start and end temperature in non-constant cooling rate conditions.

Microstructure and Mechanical Properties of ER70-Ti Steel for Gas Shielded Welding Wire

2021 ◽  
Vol 1035 ◽  
pp. 377-387
Author(s):  
Xin Wei Wang ◽  
Ren Bo Song ◽  
Zhong Zheng Pei ◽  
Xing Han Chen
Keyword(s):  
Mechanical Properties ◽  
High Strength ◽  
Rolling Temperature ◽  
Test Material ◽  
Welding Wire ◽  
Microstructure And Mechanical Properties ◽  
Final Rolling Temperature ◽  
Bainite Structure ◽  
Wire Steel ◽  
Final Rolling

In this paper, ER70-Ti welding wire steel produced by an enterprise was used as the test material. The final rolling temperature was set at 960 °C, 930 °C and 900 °C, and the spinning temperature was set at 880 °C, 860 °C and 840 °C. The results showed that the microhardness of the steel decreased from 303HV to 248HV and from 317HV to 276HV as the spinning temperature decreased from 880 °C to 840 °C. The microstructure and mechanical properties of the wires with the diameters of 5.5mm, 4mm, 2.5mm, 1.4 mm and 1.2mm were examined. It was observed that the microstructure of each sample had bainite and ferrite dual phase structure. With the decrease of wire diameter, the strength gradually increased and the ductility decreased. The experimental results show that the existence of bainite structure in the welding wire is the main reason for the high strength of the welding wire and easy fracture in drawing. Based on this, the final rolling temperature of 900 °C and the spinning temperature of 840 °C should be adopted in the production of ER70-Ti welding wire steel.

Formation of Microstructure and Texture in Intercritically Rolled C-Mn Steel

2007 ◽  
Vol 539-543 ◽  
pp. 4363-4368 ◽  
Author(s):  
Roumen H. Petrov ◽  
Leo Kestens ◽  
Yvan Houbaert
Keyword(s):  
Rolling Temperature ◽  
Accelerated Cooling ◽  
Orientation Relationships ◽  
Rolling Schedule ◽  
Rolling Pass ◽  
Final Rolling Temperature ◽  
Intercritical Region ◽  
Final Rolling ◽  
Mn Steel ◽  
Ferrite Grain Size

Series of trials were conducted on a laboratory rolling mill to evaluate the influence of intercritical rolling on the microstructure and texture of steel with 0.082%C, 1.54% Mn, 0.35% Si, 0.055%Nb and 0.078%V. Two parallel rolling schedules A and B were designed on the base of the experimentally deduced CCT diagram of the steel. In rolling schedule A the material was subjected to accelerated cooling and coiling simulation after final rolling in the intercritical region, whereas in rolling schedule B the last rolling pass in the intercritical region was replaced by a water quench at the same temperature of the intercritical rolling pass in schedule A. Microstructure and texture were characterized by means of light optical microscopy, scanning electron microscopy, EBSD and XRD. It was found that the average grain diameter and the texture depend significantly on the final rolling temperature in the intercritical region. The decrease of the intercritical rolling temperature leads to an increase of the {111}〈uvw〉 /{001}〈uvw〉 ratio, but at the same time the increase of the average ferrite grain size was also observed. A phenomenological model based on the K–S orientation relationships was used to predict the texture formation in the intercritical region.

scholarly journals A REVIEW OF MICROSTRUCTURE AND CORROSION BEHAVIOR OF CU AL NI SHAPE MEMORY ALLOY

2020 ◽  
Vol 20 (4) ◽  
pp. 362-375
Author(s):  
Nawal Mohammed Dawood
Keyword(s):  
Phase Transition ◽  
Shape Memory ◽  
Corrosion Behavior ◽  
Transformation Temperature ◽  
Critical Factor ◽  
Martensite Phase ◽  
The Other ◽  
Alloying Element ◽  
Ni Alloy ◽  
Higher Temperature

The shape memory alloys (SMAs), that consist of Cu-Al-Ni, have been established and developed for the applications used at higher temperature values due to their capability to return to its original shape when heating close to its transformation temperature. Cu-Al-Ni alloy has high value of transformation temperature and show small hysteresis as compared to the other types of SMAs. This work present a general review about how SMAs have developed by adding several metals such as, Ti, Be, B, Mn, and Zr or by changing its content (Ni or Al) by either decreasing or increasing. That might show a significant impact on the phase transition and enhancing the corrosion behavior and mechanical properties of the presented alloys. However, the transformation of the martensite phase is the critical factor that might change the properties of Cu-Al-Ni SMAs. This phase is largely affected by addition of the alloying element mentioned above. A review about effect of addition some alloying elements for enhancing the corrosion characteristics of the alloy and phase transition is presented.    

Phase Transformation Law of Nb Microalloyed Steel at Different Cooling Rates

2021 ◽  
Vol 1035 ◽  
pp. 396-403
Author(s):  
Ping Yu ◽  
Ren Bo Song ◽  
Wen Ming Xiong ◽  
Wei Feng Huo ◽  
Chen Wei ◽  
...  
Keyword(s):  
Phase Transition ◽  
Phase Transformation ◽  
Cooling Rate ◽  
Microalloyed Steel ◽  
Transition Diagram ◽  
Diffusion Type ◽  
Continuous Cooling ◽  
Type Phase ◽  
Test Steel ◽  
Nb Microalloyed Steel

Through the Gleeble3500 thermal simulation test machine, the phase transformation law of Nb microalloyed steel was studied and tested. After the compression deformation, it was cooled to room temperature at different speeds. Obtain the dynamic continuous cooling transformation diagram and the scanning structure diagram of the test steel, and then analyze the phase composition under different cooling speeds through JMatPro material performance simulation. The results show that: at a lower cooling speed (0.1°C/s), austenite decomposition is a diffusion-type phase change that takes place in a high-temperature region, and carbon atoms can diffuse sufficiently. At a moderate cooling rate (1°C/s), the bainite phase transition is a semi-diffusion phase transition in which carbon atoms are displaced in a non-cooperative thermally activated transition mode. When the cooling rate is high (15°C/s), the martensitic transformation is a non-diffusion-type transformation carried out in the low temperature region, and the atoms are directly transferred from the austenite lattice to the martensite lattice. With the increase of the cooling rate and the decrease of the transition temperature, from low-speed cooling→medium-speed cooling→high-speed cooling, respectively, the diffusion type phase transition→semi-diffusion type phase transition→the non-diffusion type phase transition. At different cooling rates, the continuous cooling transition diagram simulated by JMatPro is basically the same as the phase transition in the dynamic continuous cooling transition diagram of the test steel, which proves that the simulation prediction of the dynamic continuous cooling transition of the test steel by the JMatPro software has high accuracy and applicability.

Effect of Lower Final Rolling Temperature on Mechanical Properties of V-N Microalloyed Mild Steel

2007 ◽  
Vol 561-565 ◽  
pp. 45-48
Author(s):  
Jian Qing Qing ◽  
Bao Qiao Wu ◽  
Jie Cai Wu ◽  
Yi He
Keyword(s):  
Mechanical Properties ◽  
Mild Steel ◽  
Optical Microscope ◽  
Rolling Temperature ◽  
Second Phase ◽  
Normal Deformation ◽  
Fine Grain ◽  
Final Rolling Temperature ◽  
Second Phase Particles ◽  
Final Rolling

The samples of V-N microalloyed mild steel were obtained in duo mill with the normal deformation rate and the normal rolling temperature except final rolling temperature, which is at 780°C, 730°C and 680°C respectively. The tensile test was carried out and the microstructure was observed with optical microscope. It was found that the mechanical properties improved dramatically compared with normal process, the final rolling temperature is more than 900°C. The main reason is the fine grain size and second phase particles. With the final rolling temperature decreasing, the mechanical property further improves until the final rolling temperature of 700°C.

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