Study on phase transformation of CMnSi steel when heat treatment

After manufacturing, if the CMnSi steel was heat treatment, it would create the multi-phase microstructure consists of highly ductility ferrite matrix, martensite, bainite and amounts of austenite. Thereby, the strength and ductility of the steel were improved. In the process of improving the quality of steel, there will be two processes: the plastic deformation process and the heat treatment process. In this paper, we present the study on the microstructure and mechanical properties of CMnSi steel which was heated. The heat treatment process of CMnSi steel is a special heat treatment process including the process of heating the steel to austenite temperature at 900 °C then keeping the heat to ensure uniformity of steel. This steel was cooled quickly from austenite temperature to phase transformation temperature which had bainite transformation equal to about 400 °C (this temperature is determined by CCT diagram). The results of microstructure analysis show that by the heat treatment process, the microstructure of steel is included three main phases: ferrite, bainite, and residual austenite. The results of mechanical tests show that after the heat treatment, the strength limit of steel is 1141 MPa, the elastic limit is 943 MPa and the elongation is 36%.

Download Full-text

Study of Cu Addition on Precipitation Behaviors and Mechanical Properties in AA6082 Al-Mg-Si Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.546-549.825 ◽

2007 ◽

Vol 546-549 ◽

pp. 825-828 ◽

Cited By ~ 6

Author(s):

Man Jin ◽

Jing Li ◽

Guang Jie Shao

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Thermal Stability ◽

Treatment Process ◽

Mechanical Tests ◽

Age Hardening ◽

Heat Treatment Process ◽

Softening Process

The precipitation behaviors and microstructures of nano-precipitates in AA6082 Al-Mg-Si alloy with and without Cu additions during heat treatment process were studied using hardness measurements, TEM, mechanical tests and 3DAP. Meanwhile, the softening process of 6082 alloys with Cu and without Cu, isothermally conditioned at 250°C, has also been investigated. It was found that the rate of age hardening, mechanical properties and thermal stability are higher for the Cu-containing alloy. The TEM and 3DAP observations showed that Q’ precipitates were existed after aged at 170°C for 8h in the alloy with Cu addition. Comparing the hardness, mechanical properties and thermal stability curves, it was concluded that the Q’ precipitates play a major role in improving the age hardening kinetics and properties of 6082 alloy with Cu addition.

Download Full-text

Numerical Simulation of the H-Beam during Cooling Process

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.310.145 ◽

2013 ◽

Vol 310 ◽

pp. 145-149 ◽

Cited By ~ 1

Author(s):

Jian Liu ◽

Fu Zeng Hou ◽

Xiao Guang Yu

Keyword(s):

Mechanical Properties ◽

Numerical Simulation ◽

Heat Treatment ◽

Theoretical Basis ◽

Treatment Process ◽

Residual Austenite ◽

Heat Treatment Process ◽

Cooling Process ◽

Controlled Cooling ◽

H Beam

In order to improve the comprehensive mechanical properties of the steel, the heat treatment software COSMAP is used to simulate the rolling and controlled cooling of H-beam. The numerical simulation shows that the mechanical properties of controlled cooling can be obviously improved, when the cooling rate is controlled at 10°C/s around. Strength and hardness can be improved under the condition of ductility and toughness ensured. Meanwhile the amount of residual austenite can be reduced significantly. It provides a theoretical basis for further optimization of the heat treatment process.

Download Full-text

Failure Analysis and Study on Heat Treatment Process of Grate Bars Used in Sintering Trolley

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1061-1062.454 ◽

2014 ◽

Vol 1061-1062 ◽

pp. 454-459

Author(s):

An Min Li ◽

Ding Ma ◽

Qi Feng Zheng ◽

Ruo Huai Chen ◽

Qiang Li ◽

...

Keyword(s):

Heat Treatment ◽

Treatment Process ◽

Residual Austenite ◽

Shrinkage Porosity ◽

Heat Treatment Process ◽

Fracture Characteristics ◽

Heat Treated ◽

Primary Means ◽

Optimum Heat ◽

Optimum Heat Treatment

The as-cast grate bar structure used in sintering trolley is primarily comprised of austenite and eutectic (eutectic austenite and eutectic carbide).The austenite is dendrite, while the carbides are reticular and chrysanthemum-like. The failed grate bar structure primarily consists of ferrite, carbide, martensite and residual austenite; cavity shrinkage and shrinkage porosity exist in the structure, and the fracture exhibits typical cleavage fracture characteristics. The primary means of failure are abrasion and fracture. The secondary carbides precipitated in the sample (quenching (1050°C+2.5h)+ tempering (390°C+2.5h)) and the other one (quenching (1050°C+2.5h)+ tempering (420°C+2.5h) ) are dispersed and refined. Compared with the as-cast one, their relative abrasion resistance performances respectively are 0.8645 and 0.8752.The values of hardness and impact toughness of the samples heat-treated are greater than those of the as-cast grate bar. The optimum heat treatment process is as follows: quenching (1050°C,2.5h) + tempering (390°C~420°C,2.5h)

Download Full-text

Texture evolution, phase transformation mechanism and nanohardness of selective laser melted Ti-45Al-2Cr-5Nb alloy during multi-step heat treatment process

Intermetallics ◽

10.1016/j.intermet.2017.01.016 ◽

2017 ◽

Vol 85 ◽

pp. 130-138 ◽

Cited By ~ 20

Author(s):

Wei Li ◽

Jie Liu ◽

Yan Zhou ◽

Shifeng Wen ◽

Jiewen Tan ◽

...

Keyword(s):

Heat Treatment ◽

Phase Transformation ◽

Treatment Process ◽

Texture Evolution ◽

Heat Treatment Process ◽

Transformation Mechanism ◽

Evolution Phase ◽

Step Heat Treatment

Download Full-text

Numerical Simulation of the I-Beam during Cooling Process

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.712-715.1634 ◽

2013 ◽

Vol 712-715 ◽

pp. 1634-1637

Author(s):

Jian Liu ◽

Fu Zeng Hou ◽

Xiao Guang Yu

Keyword(s):

Mechanical Properties ◽

Numerical Simulation ◽

Heat Treatment ◽

Cooling Rate ◽

Theoretical Basis ◽

Treatment Process ◽

Residual Austenite ◽

Heat Treatment Process ◽

Cooling Process ◽

Controlled Cooling

In order to improve the comprehensive mechanical properties of the steel, the heat treatment software COSMAP is used to simulate the rolling and controlled cooling of I-beam. The numerical simulation shows that: when the cooling rate is controlled at 10 °C/s around, the mechanical properties of controlled cooling can be obviously improved. The strength and hardness can be improved on the condition of ductility and toughness ensured, while the amount of residual austenite can be reduced significantly, which provide a theoretical basis for further optimization of the heat treatment process.

Download Full-text

The Effect of Heat Treatment of Gray and Nodular Cast Iron with Ferrite Matrix on Mechanical Properties and Corrosion Rate Compared with Medium Carbon Steel

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.936.1158 ◽

2014 ◽

Vol 936 ◽

pp. 1158-1162 ◽

Cited By ~ 1

Author(s):

Mohamed A. Gebril ◽

M.S. Aldlemey ◽

Farag I. Haider

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Cast Iron ◽

Corrosion Rate ◽

Treatment Process ◽

Nodular Cast Iron ◽

Ferrite Matrix ◽

Medium Carbon Steel ◽

Heat Treatment Process ◽

Medium Carbon

In this work, the influence of heat treatment process and quenching in different quenchant media of medium carbon steel, gray and nodular cast iron with ferrite matrix on the hardness, ductility and corrosion rate of has been investigated. During this type of operations, the specimens were Austenizing at 900°C for one hour. Therefore, the specimens were quenched in different kind of oil as quenched medium (oil 20-50, oil 40, oil 90, and water as reference). The hardness , impact energy to measure the ductility, corrosion rate and microstructures were studied. From result of steel 0.47% carbon was clear increasing in hardness and decreasing in ductility with close varying values in oil quenchant kind comparing with as received specimen and water quenched one, corrosion rate decreased with heat treatment and quenching process due to formation of single face instead of double phase before heat treatment process which created galvanic cell. For gray and nodular cast iron it is noticeable that no changing in microstructure within heating for one hour at 900°C because the matrix in both cast iron types is ferrite, therefore no changing in mechanical properties under heat treatment process with time of one hour which is not sufficient to decomposition of graphite, but with comparison the hardness of gray cast iron is more than nodular one due to distribution of graphite flacks which increase the hardness and decrease the ductility as well as increasesing the corrosion rate compared with nodular cast iron. Microstructure of both types of cast iron have been studied after subjected the specimens to heat treatment at 1000°C and for 10 hours, the microstructures shown clear diffusion of some carbon in ferrite matrix around the graphite phase and under quenched some of martensite formed.

Download Full-text

Effects of Different Heat Treatments on Transformation of Residual Austenite in Bearing Steel

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.670-671.56 ◽

2014 ◽

Vol 670-671 ◽

pp. 56-60

Author(s):

H.S. Liu ◽

M.H. Wang ◽

X.Y. Ge ◽

H.S. Luo

Keyword(s):

Heat Treatment ◽

Thermal Stability ◽

Treatment Process ◽

Cryogenic Treatment ◽

Residual Austenite ◽

Bearing Steel ◽

Heat Treatment Process ◽

Austenite Content ◽

Quenching Process ◽

Thermal Stability Of

The effect of heat treatment on transformation of residual austenite in bearing steel is studied, by adding the cryogenic treatment into the normal heat treatment process. The results indicate that the residual austenite content is decreased and the hardness is improved obviously, when putting the cryogenic treatment at -70°C or lower directly behind the quenching process. While when the tempering is added between quench and cryogenic treatment, the temperature of cryogenic treatment must be much lower than -70°C to offset the thermal stability of residual austenite, which is given by tempering.

Download Full-text

Numerical Simulation of Gradient Heat Treatment Process of Cylinder Welding Component of 30Si2MnCrMoV Steel

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.664.990 ◽

2013 ◽

Vol 664 ◽

pp. 990-995

Author(s):

Q. Wang ◽

W.L. Gu ◽

D.L. Sun ◽

X.L. Han ◽

M.Y. Xue

Keyword(s):

Heat Treatment ◽

Residual Stress ◽

Phase Transformation ◽

Weld Metal ◽

Treatment Process ◽

Axial Direction ◽

Gradient Field ◽

Radial Deformation ◽

Heat Treatment Process ◽

Partial Heating

The finite element analysis method was applied to simulate the gradient field heat treatment process of a cylinder welding component of 30Si2MnCrMoV steel by software ANSYS. In the heat treatment process，the distribution of temperature field, the variation curve of residual stress with time，the distribution of residual stress along the axial direction of cylinder, and the axial and radial deformation of the specimen were calculated and the influences of partial heating area on the distribution of temperature and residual stress were analyzed. The calculating results show that the temperature in the weld metal zone and heat affected zone of welding specimens may exceed the phase transformation points during the gradient heat temperature. The residual stress and the radial deformation in the weld metal zone were greater than those in the matrix zone. The final deformation of specimen was along the axial direction. With the increase of partial heating area, the phase transformation area was increased and the residual stress was reduced effectively.

Download Full-text

Modeling the Effect of Chemistry Changes on Phase Transformation Timing, Hardness, and Distortion in Carburized 8620 Gear Steel

10.31399/asm.cp.ht2021p0309 ◽

2021 ◽

Author(s):

Jason Meyer ◽

Stefan Habean ◽

Dan Londrico ◽

Justin Sims

Keyword(s):

Heat Treatment ◽

Phase Transformation ◽

Treatment Process ◽

Low Cost ◽

Low Carbon Steel ◽

Alloy Element ◽

Case Hardening ◽

Heat Treatment Process ◽

Low Carbon ◽

Using Data

Abstract AISI 8620 low carbon steel is widely used due to its relatively low cost and excellent case hardening properties. The nominal chemistry of AISI 8620 can have a large range, affecting the phase transformation timing and final hardness of a carburized case. Different vendors and different heats of steel can have different chemistries under the same AISI 8620 range which will change the result of a well-established heat treatment process. Modeling the effects of alloy element variation can save countless hours and scrap costs while providing assurance that mechanical requirements are met. The DANTE model was validated using data from a previous publication and was used to study the effect of chemistry variations on hardness and phase transformation timing. Finally, a model of high and low chemistries was executed to observe the changes in hardness, retained austenite and residual stress caused by alloy variation within the validated heat treatment process.

Download Full-text