scholarly journals Effect of Heat Treatments on Microstructural Evolution and Tensile Properties of 15Cr12MoVWN Ferritic/Martensitic Steel

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1271
Author(s):  
Tingwei Ma ◽  
Xianchao Hao ◽  
Ping Wang
Keyword(s):  
Heat Treatment ◽  
Tensile Properties ◽  
Room Temperature ◽  
Treatment Process ◽  
Martensitic Steel ◽  
Heat Treatment Process ◽  
Lath Width ◽  
Optimum Heat ◽  
Martensitic Lath ◽  
Optimum Heat Treatment

In this study, the phase transformation temperature of 15Cr12MoVWN ferritic/martensitic steel was determined by differential scanning calorimetry to provide a theoretical basis for the design of a heat treatment process. An orthogonal design experiment was performed to investigate the relationship between microstructure and heat treatment parameters, i.e., normalizing temperature, cooling method and tempering temperature by evaluating the room-temperature and elevated-temperature tensile properties, and the optimum heat treatment parameters were determined. It is shown that the optimized heat treatment process was composed of normalizing at 1050 °C followed by air cooling to room temperature and tempering at 700 °C. Under the optimum heat treatment condition, the room-temperature tensile properties were 1014 MPa (UTS), 810.5 MPa (YS) and 18.8% (elongation), while the values are 577.5 MPa (UTS), 469 MPa (YS) and 39.8% (elongation) tested at 550 °C. The microstructural examination shows that the strengthening contributions from microstructural factors were the martensitic lath width, dislocations, M23C6, MX and grain boundaries of prior austenite grain (PAG) in a descending order. The main factors influencing the tensile strength of 15Cr12MoVWN steel were the martensitic lath width and dislocations.

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

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)

scholarly journals Hardness and Conductivity of Die Forged ZYK530 Magnesium Alloy

2021 ◽  
Author(s):  
Fenghong CAO ◽  
Yaohui XU ◽  
Chang CHEN ◽  
Zhaohui QIN ◽  
Chi DENG
Keyword(s):  
Heat Treatment ◽  
Electrical Conductivity ◽  
Treatment Process ◽  
Mg Alloy ◽  
Heat Treatment Process ◽  
Optimum Heat ◽  
The Relationship ◽  
Optimum Heat Treatment ◽  
Good Agreement ◽  
Peak Value

The relationship among the microstructure, hardness and electrical conductivity of the as-forged ZYK530 Mg alloy after heat treatment was analyzed and studied using a microscope, X-Ray Diffractometer, eddy current conductivity meter, and Vickers microhardness tester, to explore optimum heat treatment process of ZYK530 Mg alloy. The results show that: with the prolongation of holding time, the electrical conductivity and microhardness show the same change trend, both of which show an oscillatory upward trend, and then decrease in an oscillatory downward trend after reaching the  peak value. There is a linear positive correlation between the conductivity and the hardness, and the fitting results of the conductivity and hardness are in good agreement with the measured results; combined with the actual production, when the heat-treatment is 480 ℃ × 8 h + 220 ℃ × 3 h, the highest hardness is 79.2 HV, the electroconductivity is 36.2%IACS, and the comprehensive performance is the best, which is the best heat treatment process.

Numberical Simulation of Welding Deformation under Different Conditions

2012 ◽  
Vol 538-541 ◽  
pp. 1439-1442
Author(s):  
Qing Yang ◽  
Shu Jun Xie ◽  
Hai Tao Gao
Keyword(s):  
Heat Treatment ◽  
Room Temperature ◽  
Treatment Process ◽  
Three Dimensional ◽  
Angular Distortion ◽  
Solid Model ◽  
Heat Treatment Process ◽  
Cooling Process ◽  
Finite Element Software ◽  
Set Up

To simulate the welding and heat treatment process of the Q345 plate with V-groove, Finite element software ANSYS was employed. A reasonable three-dimensional solid model was set up by using element birth and death technology to simulate the formation of the weld. Constraint was applied on both sides of the base metal in the welding and cooling process. Then constraint was removed when the specimen was cooled to room temperature, the angular distortion of welding increases by 75.03% after the constraint is removed. Then heat treatment was conducted on the plate of which the constraint was removed. The deformation results show that after heat treatment the angular distortion is reduced to 30.37% of the value before heat treatment.

Heat treatment of electron beam melted (EBM) Ti-6Al-4V: microstructure to mechanical property correlations

2018 ◽  
Vol 24 (4) ◽  
pp. 774-783 ◽  
Author(s):  
Srinivasan Raghavan ◽  
Mui Ling Sharon Nai ◽  
Pan Wang ◽  
Wai Jack Sin ◽  
Tao Li ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Mechanical Property ◽  
Electron Beam ◽  
Treatment Process ◽  
Heat Treatment Process ◽  
Post Processing ◽  
Content Type ◽  
Optimal Heat ◽  
Optimal Heat Treatment ◽  
Lath Width

Purpose The paper presents a wide range of post processing heat treatment cycles performed to Electron Beam Melted (EBM) Ti6Al4V alloy and establishes correlations of heat treat process to microstructure and mechanical property (microhardness). The research also identifies the optimal heat treatment to obtain the best microstructure and mechanical properties (hardness and tensile). Design/methodology/approach Rectangular bars fabricated using EBM was used to study the different heat treatment cycles. A variety of heat treatments from sub ß-transus, super ß-transus, near ß-transus and solution aircool plus ageing were designed. After the heat treatment process, the samples were analysed for, α lath width, prior ß grain size, microhardness and nanohardness. Tensile tests were done for the heat treated samples showing most refined α lath structure with uniform globular grains. Findings A clear correlation was observed between α lath width and the microhardness values. The solution aircooled plus aged samples exhibited the best refinement in α-ß morphology with uniform equiaxed grains. The tensile properties of the solution aircooled plus aged samples were comparable to that of the EBM printed samples and better than ASTMF1472 specifications. Originality/value There is hardly any prior work related to post processing heat treatment of EBM built Ti6Al4V other than HIP treatments. The variety of heat treatment cycles and its influence in microstructure and properties, studied in this research, gives a clear understanding on how to tailor final microstructures and select the optimal heat treatment process.

Research on the Optimization of Heat Treatment Process and the Abrasive Impact Wear Mechanism of 70Mn Steel

2013 ◽  
Vol 395-396 ◽  
pp. 308-312
Author(s):  
Peng Deng ◽  
Ren Bo Song ◽  
Ting Sun ◽  
Xu Wang
Keyword(s):  
Heat Treatment ◽  
Wear Mechanism ◽  
Treatment Process ◽  
Orthogonal Experiment ◽  
Optical Microscope ◽  
Experimental Results ◽  
Experimental Result ◽  
Heat Treatment Process ◽  
Impact Wear ◽  
Optimum Heat

This research was conducted on the influence of heat treatment parameters on the mechanical properties and abrasive wear resistance of 70Mn steel through experimental results. Orthogonal experiment was applied for designing heat treatment process and acquired optimal heat treatment parameters. The experimental results showed that the optimum heat treatment process was firstly heated to 830°C preserved for 60min, and rapidly quenched, then tempered at 200°C for 80min. Abrasive impact wear experiment was performed on MLD-10 tester, under which the wear surface and the subsurface were observed through scanning electron microscope and optical microscope. According to the experimental result, abrasive impact wear mechanism was analyzed. The results showed that plastic deformation fatigue and gouging wear were the primary mechanisms of abrasive impact wear, together with a small amount of furrow and cutting.

scholarly journals Room temperature ionic liquids in a heat treatment process for metals

RSC Advances ◽  
2014 ◽  
Vol 4 (98) ◽  
pp. 55077-55081 ◽  
Author(s):  
C. Schmidt ◽  
M. Beck ◽  
M. Ahrenberg ◽  
C. Schick ◽  
O. Keßler ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Ionic Liquids ◽  
Room Temperature ◽  
Treatment Process ◽  
Room Temperature Ionic Liquids ◽  
Heat Treatment Process

scholarly journals The Effects of Al3(Sc, Zr) Precipitation Phase on Selective Laser Melting Al-Mg-Sc-Zr alloy: Microstructure, Mechanical properties and Fatigue resistance

2021 ◽  
Author(s):  
Liang-Yan Lee ◽  
Kai-Chieh Chang ◽  
Jun-Ren Zhao ◽  
Fei-Yi Hung
Keyword(s):  
Heat Treatment ◽  
Room Temperature ◽  
Treatment Process ◽  
Single Stage ◽  
Heat Treatment Process ◽  
Two Stage ◽  
The Matrix ◽  
Melting Pool ◽  
Stage Heat Treatment ◽  
Zr Alloy

Abstract In this study, an Al-Mg-Sc-Zr alloy fabricated through selective laser melting (SLM) was subjected to a single-stage heat-treatment process and a two-stage heat-treatment process to determine the effect of heat treatment on the tensile properties and fatigue properties of the alloy at room temperature and high temperatures. The results indicated that heat treatment caused the precipitation of Al3(Sc, Zr), thus increasing the tensile strength. The dynamic strain aging of the SLM Al-Mg-Sc-Zr alloy disappeared as the tensile temperature increased. The alloy exhibited the highest tensile strength after it was subjected to the single-stage heat treatment at both room temperature and high temperatures owing to the precipitated phase distribution at the melting pool boundaries. However, fatigue resistance and high-temperature necking of the as-printed SLM Al-Mg-Sc-Zr alloy were problems that could not be resolved with the single-stage heat treatment. In the two-stage heat treatment, the precipitated phases exhibited a uniform distribution in the matrix, thereby reducing the high-temperature necking phenomenon. The two-stage heat treatment helped reduce the melting pool interface effect and strengthen the matrix, restricting the propagation of fatigue cracks and increasing the fatigue life of materials.

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