A Brief Review on Validation for Heat Treatment Simulation

2021 ◽  
Author(s):  
Kyozo Arimoto
Keyword(s):  
Heat Treatment ◽  
Measurement Data ◽  
Strain Analysis ◽  
Experimental Results ◽  
Stress Distributions ◽  
Simulation Functions ◽  
Basic Functions ◽  
Hardness Prediction ◽  
Quenched Steel ◽  
Complex Phenomena

Abstract Heat treatment simulation has progressed to the stage where several commercial software are available. Validations of simulation functions using experimental results contributed to this realization. Organizing information on the validations may be effective for maintaining the functions and educating users about the nature of the phenomena. For this reason, the author here briefly reviews mainly his validation cases. Since experiments using specimens having relatively simple shapes can reveal the essence of complex phenomena, the results have been used in the validations. When the basic functions such as heat transfer, phase transformation, latent heat, and hardness prediction were comprehensively validated in the early stages of software development, the author used experimental results of the inverse hardening in quenched steel cylinders. After that, his validations of the software at the stage where adding stress and strain analysis functions, used effectively measurement data of length and diameter changes, and residual stress distributions in normally quenched steel cylinders. While, it was also worth to validate curving in long specimens cooled unevenly, which included a case of specimens with a similar cross-section to the Japanese sword. In addition, the author validated distortions and residual stresses in carburized and quenched, induction hardened, and also nitrided specimens.

The Mechanical Characteristics and Sealing Performance Evaluation of Bolted Pipe Flange Connections With Metallic Flat Gaskets Subjected to Internal Pressure

2016 ◽  
Author(s):  
Koji Kondo ◽  
Koji Sato ◽  
Satomi Takahashi ◽  
Toshiyuki Sawa
Keyword(s):  
Plastic Deformation ◽  
Mechanical Characteristics ◽  
Experimental Results ◽  
Leak Rate ◽  
Effect Of Temperature ◽  
Load Factor ◽  
Stress Distributions ◽  
Bolt Preload ◽  
Sealing Performance ◽  
Higher Temperature

Bolted pipe flange connections with metallic gaskets have been used under higher pressure as well as higher temperature. However, a few researches on the mechanical characteristics in connections with metallic gaskets have been carried out. It is necessary to examine the mechanical characteristics such as the contact gasket stress distributions which govern the sealing performance, the deformation of the metallic gaskets, changes in axial bolt forces and the hub stress under higher pressure and temperature. In the present paper, the objectives are to examine the changes in axial bolt forces, the hub stress and the contact gasket stress distributions and the sealing performance of the pipe flange connections with metallic flat gaskets. Firstly, the mechanical characteristics of the connections under higher pressure are analyzed using FEA. Then, experiments were carried out to measure the load factor, the hub stress and the leak rate (the sealing performance). The relationship between the average contact gasket stress and the leak rate was measured using platen device at room temperature. The FEA results are fairly coincided with the experimental results. It is shown that the leak rate decreases as the contact gasket stress increases and when the plastic deformation of gaskets occurs, the sealing performance increases. The leak rate was measured in the range of 10−4∼10−7 [Pa·m3/s]. It is found that the sealing performance increases as the gasket width increase in the elastic deformation range while it is independent of the gasket width when the plastic deformation occurs. The effect of temperature on the mechanical characteristics of the connection is also examined. The FEA results are in a fairly good agreement with the experimental results. It is found that the sealing performance increases as the temperature increases. In addition, a method how to determine the bolt preload for increasing the sealing performance is proposed.

Study on the Truck Scale Cheating Automatic Monitoring System Based on the GPRS

2013 ◽  
Vol 703 ◽  
pp. 240-243 ◽  
Author(s):  
Yan Jun Zhao ◽  
Shou Guang Cheng ◽  
Bin Qu
Keyword(s):  
Monitoring System ◽  
Measurement Data ◽  
Experimental System ◽  
Automatic Monitoring ◽  
Experimental Results ◽  
Pneumatic Conveying ◽  
Automatic Monitoring System ◽  
On Line ◽  
Conveying System

The truck scale is more and more applied on the weighing system. To seek illegal profits, many kinds of truck scale cheating method is found in the weighing system. To monitoring the truck scale cheating method, the truck scale cheating automatic monitoring system based on the GPRS is brought out in this paper. The truck scale cheating automatic monitoring system is designed. The monitoring system includes three parts: the monitoring terminal, the GPRS transmission module and the upper monitoring system. The truck scale measurement data of the sensors are collected by the monitoring terminal and sent to the upper monitoring system through the GPRS module. The experimental system is established on the pneumatic conveying system and the experiment is carried out. The experimental results show that the automatic monitoring system can on-line monitor the truck scale cheating method and improves the security of the truck scale weighing system.

Surface Oxidation Behaviour of Cubic BN Powders

2014 ◽  
Vol 602-603 ◽  
pp. 544-547
Author(s):  
Xin Yan Yue ◽  
Yue Zhang ◽  
Jian Jun Wang ◽  
Wei Wang ◽  
Hong Qiang Ru
Keyword(s):  
Heat Treatment ◽  
Surface Oxidation ◽  
Mass Gain ◽  
Oxidation Behaviour ◽  
Experimental Results ◽  
Oxidation Temperature ◽  
Oxidation Reactions ◽  
Oxidation Treatment ◽  
Treatment Processes

In order to improve the sinterability of the cBN, surface oxidation treatment was conducted to form a B2O3 film on the surface of the cBN powders. The cBN powders (d50 = 7.5 μm) were used as original powders. The heat treatment processes were 500, 800, 900, 950, 980 and 1000 °C holding for 30 minutes, respectively. The oxidation reactions which probably happened were calculated based on the thermodynamics. The experimental results showed that the oxidation starting temperature of cBN powders was higher than 800 °C. The higher the oxidation temperature, the greater the mass gain of the cBN powders.

Influence of Residual Stress on the Thermal Expansion Behavior of Electroformed Nickel Layers

2013 ◽  
Vol 662 ◽  
pp. 511-514
Author(s):  
Yi Chun Liu ◽  
Jia Min Zhang ◽  
Jian Hong Yi
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Thermal Expansion ◽  
Theoretical Analysis ◽  
Subsequent Heat Treatment ◽  
Experimental Results ◽  
Thermal Expansion Behavior ◽  
Expansion Behavior ◽  
Electroformed Nickel ◽  
The Relationship

Nickel layers with tensile or pressure residual stress were prepared by electroforming technique from two kinds of electrolyte. Subsequent heat treatment was adopted to get the stress released. The coefficients of thermal expansion (CTEs) were measured with a thermal dilatometer and the relationship between residual stress and the measured CTEs was revealed both from experimental results and theoretical analysis.

Residual Stress Analysis Considering Phase Transformation and Transformation Plasticity for Heat-Treated Large Size Shaft

2016 ◽  
Vol 725 ◽  
pp. 647-652 ◽  
Author(s):  
Yusuke Yanagisawa ◽  
Yasuhiro Kishi ◽  
Katsuhiko Sasaki
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Phase Transformation ◽  
Air Cooling ◽  
Water Cooling ◽  
Stress Distributions ◽  
Transformation Plasticity ◽  
Large Size ◽  
Heat Treated ◽  
Good Agreement

The residual stress distributions of the forgings after both water-cooling and air-cooling were measured experimentally. The residual stress occurring during the heat-treatment was also simulated considering the phase transformation and the transformation plasticity. A comparison of the experiments with the simulations showed a good agreement. These results shows that the transformation plastic strain plays an important role in the heat treatment of large forged shafts.

Predictive Kinetics-based Model for Shock-activated Reaction Synthesis of Ti3SiC2

2005 ◽  
Vol 20 (6) ◽  
pp. 1476-1484
Author(s):  
Jennifer L. Jordan ◽  
John A. Pelesko ◽  
Naresh N. Thadhani
Keyword(s):  
Heat Treatment ◽  
Activation Energy ◽  
Steady State ◽  
Predictive Model ◽  
Heat Dissipation ◽  
Experimental Results ◽  
Reaction Synthesis ◽  
Synthesis Conditions ◽  
Type Reaction ◽  
Activated State

A kinetics model based on mass and heat transport has been developed for Ti3SiC2 formation via shock-activated reaction synthesis of powder precursors. The model allows prediction of heat treatment conditions under which an otherwise steady-state reaction is taken over by a “run-away” combustion-type reaction during post-shock reaction synthesis of Ti3SiC2. Shock compression of Ti, SiC, and graphite precursors generates a densely packed highly activated state of reactants, which lowers the activation energy and results in an increased rate of formation of Ti3SiC2 at a lower temperature and in shorter times. The predictive model correlated with experimental results of fraction reacted as a function of time at heat-treatment temperatures of 1400 and 1600 °C illustrates an increased rate of reaction due to lowering activation energy, which also results in the reaction at 1600 °C being taken over by a “run-away” combustion-type reaction, as the rate of heat release due to reaction exceeds the rate of heat dissipation through the compact. Correlation of the model with experimental results illustrates that the predictive model can be used to optimize reaction synthesis conditions in shock-densified compacts of Ti3SiC2-forming powder precursors, to better understand the processes leading to a steady-state reaction being taken over by the combustion mode.

Fluidized bed heat treatment of aluminum cast components

2004 ◽  
Vol 120 ◽  
pp. 555-562
Author(s):  
D. Apelian ◽  
S. K. Chaudhury
Keyword(s):  
Heat Treatment ◽  
Fluidized Bed ◽  
Processing Time ◽  
Reaction Times ◽  
Experimental Results ◽  
Fluidized Bed Reactors ◽  
The Past ◽  
Conventional Furnace ◽  
Time Required ◽  
Solutionizing Time

Heat Treatment and post casting treatments of cast components has always been an important step in the control of microstructure, and resultant properties. In the past, the solutionizing, quenching and ageing process steps may have “required” in total over 20 hours of processing time. With the advent of fluidized bed reactors (FB), processing time has been dramatically reduced. For example, instead of 8-10 hours solutionizing time in a conventional furnace, the time required in FB is less than an hour. Experiments with Al-Si-Mg alloy, (both modified with Sr, and unmodified) were performed, having different diffusion distances (different DAS), and for different reaction times and temperatures. Both the model and the experimental results are presented and discussed.

Residual Stress Prediction for Non-Axisymmetric Vessel Penetration Welds

2008 ◽  
Author(s):  
Kazuo Ogawa ◽  
Nobuyoshi Yanagida ◽  
Koichi Saito
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Three Dimensional ◽  
Measurement Data ◽  
Fe Model ◽  
Stress Distributions ◽  
Dimensional Finite Element ◽  
Stress Prediction ◽  
Three Dimensional Finite Element ◽  
Good Agreement

Residual stress distribution in an oblique nozzle jointed to a vessel with J-groove welds was analyzed using a three-dimensional finite element method. All welding passes were considered in a 180-degree finite element (FE) model with symmetry. Temperature and stress were modeled for simultaneous bead laying. To determine residual stress distributions at the welds experimentally, a mock-up specimen was manufactured. The analytical results show good agreement with the experimental measurement data, indicating that FE modeling is valid.

Machine Design for Multiscale Nitinol Annealment Process and End Product Performance Analysis

2020 ◽  
Author(s):  
Amanda Skalitzky ◽  
Stuart Coats ◽  
Ramsis Farag ◽  
Austin Gurley ◽  
David Beale
Keyword(s):  
Heat Treatment ◽  
Treatment Process ◽  
Heat Treating ◽  
Experimental Results ◽  
Heat Treatment Process ◽  
Scanning Calorimetry ◽  
Niti Wire ◽  
Annealing Temperatures ◽  
Conventional Heat Treatment ◽  
Post Production

Abstract The functional properties of Nitinol (NiTi) are set by composition, production process, and post-production heat treatment and cold working. Post-production heat treating is dependent on two main parameters: anneal temperature and aging time. Most heat-treating processes performed by researchers generally consist of simple temperature soaks at specified aging times. However, there are drawbacks to this method. More complex heat treatments can result in performance improvements, but they are difficult to implement and often proprietary to manufacturers and therefore not widely used by researchers. By designing a Continuously-Fed heat treatment System (CFS), this work demystifies this complex heat-treatment process by rapidly heat-treating NiTi wire samples across a range of annealing temperatures, soak times, and tensions with little human intervention. This automated process ensures samples are created in a consistent manner and results in a much more consistent end-product when compared to conventional heat-treating methods. Using the CFS, a gamut of samples with varying annealing temperatures (400–550°C) and aging times (1–3 minutes) were created with 0.25mm diameter high-temperature actuator wire initially in the ‘as-drawn’ condition. Differential Scanning Calorimetry (DSC) analysis was performed to determine how the transition temperature(s) change with the various heat-treating parameters and the mechanical properties of the wire were determined utilizing a tensile test. The experimental results demonstrate the benefits of the CFS and are compared to those of a more conventional heat treatment process. Experimental results show that high-performance Nitinol actuator behavior can consistently be achieved using the CFS. Optimal heat treatment processes can be determined quickly experimentally.

scholarly journals Analysis on three typical abnormal microstructures of overhead power line suspension clamps

2020 ◽  
Vol 165 ◽  
pp. 06029
Author(s):  
Weike Liu ◽  
Mengbao Zhou ◽  
Jiarui Hu ◽  
Songqi Wu ◽  
Xianhui Cao ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Hardness Measurement ◽  
Power Line ◽  
Experimental Results ◽  
Flake Graphite ◽  
Quality Inspection ◽  
X Ray ◽  
Metallographic Observation ◽  
Annealing Heat Treatment ◽  
Overhead Power Line

This article lists three typical abnormal microstructures of overhead power line suspension clamps, including inclusion, flake graphite and cementite network. A series of tests including macro check, hardness measurement, composition tests, Energy-dispersive x-ray analysis and metallographic observation have been carried out. The experimental results showed that the causes of abnormal microstructures mainly include: high content of impurities, flake graphite blank and unfulfilled annealing heat treatment. It is suggested to strengthen the supervision on suspension clamps before using, and focus on the quality inspection of metallographic structure and composition.

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