Application of numerical simulation of heat treatment in industry

2004 ◽  
Vol 120 ◽  
pp. 753-760
Author(s):  
M. Slováček
Keyword(s):  
Numerical Simulation ◽  
Heat Treatment ◽  
Residual Stresses ◽  
Input Data ◽  
Applied Mechanics ◽  
Heat Treated

Heat treatment and especially quenching causes distortion and sometimes cracking of a quenched part. To eliminate these undesired by-effects the whole cycle of heat treatment is simulated by FEM, which makes possible a complete metallurgical, thermal and thermoplastic calculation. The goal of this simulation is to bring the whole cycle of heat treatment to optimum - to reach the lowest level of residual stresses possible at its end and to meet the mechanical qualities required by the customer. A lot of complete numerical simulation of heat treatment were done at the Institute of Applied Mechanics (IAM) by the SYSWELD code, mainly the heat treatment of big shafts and plates for Vitkovice Company. The Vitkovice, JSC produces ship-shafts of large dimensions (diameter 2.5 m, length 10m) and other products which are forged and consequently heat treated. Heat treatment consists of quenching (in water, air and oil), and then tempering follows.The whole simulation was divided into two parts. The aim of the first part was to find correct input data for calculation..The second part consisted of heat treatment simulation with real models.

A Study of the Influence of Local Heat Treatment on the Structure of Welded Titanium Pipelines

2021 ◽  
Vol 410 ◽  
pp. 37-41
Author(s):  
Natalia A. Astafeva ◽  
Andrey A. Balanovskiy ◽  
Anna A. Pershina
Keyword(s):  
Heat Treatment ◽  
Residual Stresses ◽  
Titanium Alloys ◽  
Welded Joints ◽  
Treatment Method ◽  
Local Heat ◽  
Optical Metallography ◽  
Heat Treated ◽  
Weld Structure ◽  
Heat Treatment Method

The article analyzes the results of a study of the influence of zonal heat treatment on the structure of welded joints of pipeline elements made of titanium alloys Ti-3.5Al-1.5Mn. In the manufacture of such structures, the TIG welding method is used to join pipe elements, after which the heat treatment method can be used to relieve residual stresses. The experiments have confirmed the effectiveness of zonal heat treatment preceded by welding. It was revealed that for welded joints made of titanium alloys, heat treatment can stabilize the structure. In experiments conducted by the method of optical metallography, the structure of heat treated and untreated welded joints was investigated. The influence of heat treatment on the weld structure and heat-affected zone was identified.

Recent Applications of XSA in Heat Treatment and Fatigue of Steels

1983 ◽  
Vol 27 ◽  
pp. 179-190
Author(s):  
E. Macherauch ◽  
B. Scholtes
Keyword(s):  
Heat Treatment ◽  
Residual Stresses ◽  
Experimental Work ◽  
Carbon Steels ◽  
X Ray ◽  
Lattice Strains ◽  
Heat Treated ◽  
Computer Controlled

This paper is intended to give an exemplary review of recent investigations performed in the X-ray laboratory of the Institut für Werkstoffkunde I of the Universität Karlsruhe, FRG, concerning particular problems of residual stresses of heat-treated and fatigued steels. The experimental work was mainly performed with computer-controlled Karlsruhe type ψ-diffractometers. If linear distributions of residual lattice strains occurred the sin2ψ-method was applied to determine residual stresses. The experiments were performed with plain carbon steels of 0.22 and 0.45 wt.-% carbon (German grade Ck 22 and Ck 45) and some low alloyed steels.

Numerical Simulation of Residual Stresses during the Heat Treatment of Dies Made of Hot Work Tool Steel

2006 ◽  
Vol 524-525 ◽  
pp. 433-438 ◽  
Author(s):  
Christian Redl ◽  
Christian Friesenbichler ◽  
Volker Wieser
Keyword(s):  
Numerical Simulation ◽  
Heat Treatment ◽  
Residual Stresses ◽  
Phase Distribution ◽  
Production Cycle ◽  
Treatment Model ◽  
The Finite Element Method ◽  
Quenching Media ◽  
Treatment Processes ◽  
Gas Quenching

Residual stresses are of great importance during the entire production cycle of high-grade steels. The use of modern tools based on the finite element method is steadily increasing to optimize heat treatment processes. As for industrial purposes it is often not possible to measure the entire set of material data a sensitivity analysis shows the relative influence of material properties related to phase transformation on the residual stresses during hardening. Subsequently the application of the numerical heat treatment model is shown on two examples: The magnitudes of residual stresses during the quenching of a forged bar in different quenching media are compared. The paper concludes with a numerical simulation of the heat treatment of a die used for extrusion processes. Phase distribution and residual stresses after gas quenching of the tool are presented.

A Method for Field Evaluation of Heat Treatment to Identify Vessels That Are Susceptible to Sulfide Stress Cracking

2017 ◽  
Author(s):  
Guillermo Ramirez ◽  
Kollin Kenady ◽  
Joshua E. Jackson
Keyword(s):  
Heat Treatment ◽  
Residual Stresses ◽  
Pressure Vessels ◽  
Destructive Testing ◽  
Stress Cracking ◽  
Heat Treated ◽  
Sulfide Stress ◽  
Sulfide Stress Cracking ◽  
Favorable Conditions ◽  
Non Destructive

Inadequate heat treatment in the head and head-to-shell weld areas of a low-pressure separator vessel was determined to have led to conditions which allowed for the development of sulfide stress cracks, and ultimately resulted in rupture of the vessel. This determination was made through the use of destructive testing and failure analysis of the ruptured vessel. Generally, verification of vessel heat treatment is done through review of temperature recordings from manufacturing documentation or third party verification at the time of fabrication. Unfortunately, heat treatment records of pressure vessels are often misplaced, lost during acquisitions/mergers, or simply never existed. Under the assumption that these vessels were adequately heat treated, the vessel’s owners do not normally take into consideration the high residual stresses which create favorable conditions for sulfide stress cracking (SSC) and other stress corrosion cracking type damage mechanisms. In this case, cold formation of the head resulted in high residual stresses in the flange and knuckle regions. The welds, which had not been properly post-weld heat treated, similarly had high residual stresses. These high stresses resulted in favorable conditions for the SSC to occur when exposed to a corrosive environment such as oil and gas operations. In an effort to prevent similar events from occurring in the future, it was determined to be necessary to evaluate other vessels for inadequate heat treatment that may result in SSC. A non-destructive approach was investigated to evaluate vessels, especially in the absence of the aforementioned heat treatment records, to determine if the formed heads and heat affected zones after welding had adequate heat treatment. A method was developed to identify vessels without adequate heat treatment utilizing standard non-destructive testing techniques. There is the potential that many other low pressure vessels in lethal service could have received inadequate heat treatment. This methodology can therefore be used to determine the heat treatment state for these pressure vessels without destructive testing.

Research on Gradient Heat Treatment of Dual-Property Disk for Alloy FGH96

2013 ◽  
Vol 747-748 ◽  
pp. 783-787
Author(s):  
Yu Wang ◽  
Jin Wen Zou ◽  
Guo Qing Zhang ◽  
Wu Xiang Wang
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Heat Treatment ◽  
Transient Temperature ◽  
Heating Process ◽  
Fixture Design ◽  
Dual Property ◽  
Transient Temperature Field ◽  
Heat Treated ◽  
Treatment Experiment

The transient temperature field in the dual-property disk of alloy FGH96 was investigated during the solution heating process of the gradient heat treatment by numerical simulation. The temperature curves for the different locations of the disk were attained. Then, the gradient heat treatment experiment was carried out, and the heat profiles were obtained. The numerical and the experimental results were almost consistent. The method of heat transfer for the bore of the disk was changed evidently through effective fixture design during the gradient heat treatment. The gradient of temperature (ΔT) can reach 121 or more, which lead to a supersolvus heat treated rim and subsolvus heat treated bore for the disk.

scholarly journals Influence of Heat Treatment on Residual Stress in Cold-Forged Parts

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Frederico Ozanan Neves ◽  
Thiago Luis Lara Oliviera ◽  
Durval Uchoas Braga ◽  
Alex Sander Chaves da Silva
Keyword(s):  
Heat Treatment ◽  
Residual Stresses ◽  
The Body ◽  
Thermal Treatments ◽  
Cold Forming ◽  
Heat Treated ◽  
Forged Parts ◽  
Aisi 1045 Steel ◽  
Aisi 1045 ◽  
1045 Steel

Residual stresses are those stresses that remain in a body when there is no external load applied. Numerous factors can induce residual stresses in the material, including cold forming. Thermal treatments of steel are widely used because they can improve the mechanical properties of the steel, such as toughness, tenacity, and resistance; however, thermal treatments can also produce residual stresses. This study aims to analyze the residual stresses present in a cold-forged part after heat treatments. Half-cylinder samples of AISI 1045 steel were cold-forged, and a wedge tool was pressed into their surface, causing a strain gradient. The samples were then heat-treated by annealing, normalizing, quenching, or quenching and tempering. A numerical simulation was also performed to aid in choosing the measurement points in the samples. The results show that residual stresses are dependent on the heat treatment and on the intensity and nature of previous residual stresses in the body.

scholarly journals Residual Stress Measurement in Heat Treated Cylindrical Components

2021 ◽  
Author(s):  
M. Belassel ◽  
J. Pineault ◽  
M. Bolla ◽  
M. Brauss
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Residual Stresses ◽  
Stress Measurement ◽  
Microstructural Characterization ◽  
Plain Carbon Steel ◽  
X Ray Diffraction ◽  
Treatment Processes ◽  
Heat Treated ◽  
Xrd Techniques

Abstract Heat treatment processes can generate steep residual stress (RS) gradients and plastic deformation in metal components due to differential cooling and other effect such as phase transformation. The magnitude of residual stresses generated, and how quickly they vary spatially, will depend upon the material itself and the temperature gradients introduced during the heat treatment process. X-ray diffraction (XRD) techniques can be used to characterize residual stresses, as well as microstructural changes, including dislocation density and particle size in heat treated components. Plain carbon steel cylinders were heat treated, quenched and characterized using these methods. Residual stress measurements were performed via XRD using the Sin2Ψ technique and microstructural characterization was evaluated using the associated peak widths. Measurements were carried out both at the surface and through depth using electropolishing. The results indicate triaxial stress gradients exist in all samples investigated, with concomitant varying microstructural characteristics.

Residual Stress Enhancement in 3D Printed Inconel 718 Superalloy Treated by Ultrasonic Nano-Crystal Surface Modification

2017 ◽  
Author(s):  
Kuldeep Singh Sidhu ◽  
Jing Shi ◽  
Vijay K. Vasudevan ◽  
Seetha Ramaiah Mannava
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Surface Modification ◽  
Residual Stresses ◽  
Inconel 718 ◽  
Crystal Surface ◽  
High Temperature Strength ◽  
Heat Treated ◽  
Wide Range ◽  
Inconel 718 Superalloy

Inconel 718 (IN718) is a nickel based Ni-Cr-Fe super alloy. It has a unique set of properties such as good workability, corrosion resistance, high temperature strength, favorable weldability and excellent manufacturability. Due to its wide range of applications, IN718 is an alloy of great interest for many industries. Meanwhile, additive manufacturing assisted with laser has caught much interest from researchers and practitioners in the past three decades. In this study, IN718 alloy coupons are manufactured by selective laser melting (SLM) technique. The SLMed IN718 alloys are treated by ultrasonic nanocrystal surface modification (UNSM), and the residual stress distributions underneath the surfaces are measured. It is found that residual stress mostly tensile is induced while building the part by the SLM technique. The tensile stresses can be reduced to almost zero value by post heat treatment. Moreover, the heat treatment helps to homogenize the microstructure, and results in the increase in hardness. More importantly, it is observed that UNSM effectively induces compressive residual stresses in the as-built and heat-treated parts. The residual stresses of compressive nature in as built parts has depth of around 530 μm where as in heat treated parts has a depth of around 530μm.

Residual Stress and Shape Distortion in High-Strength Tool Steels

1967 ◽  
Vol 11 ◽  
pp. 411-417
Author(s):  
L. B. Gulbransen ◽  
A. K. Dhingra
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Residual Stresses ◽  
Tool Steel ◽  
High Performance ◽  
Diffraction Method ◽  
High Strength ◽  
Angular Distortion ◽  
Shape Distortion ◽  
Heat Treated

AbstractOne of the major problems that has plagued the tool and die maker for many years and more recently has come to the attention of the manufacturer of missiles and high-performance aircraft is the problem of shape distortion which occurs during heat treatment in the high-strength tool and die steels. Not only is shape distortion a problem in the heat treatment and use of these materials, but the origin of shape distortion has been a controversial issue among metallurgists for many years. The quantitative measurement of shape distortion on heat-treated steels is simply carried out hy machining standard shape samples, in this case, an L-shaped sample, and making a measurement of the variation after heat treatment from the 90° of the original 90° angle of the L. It is usually assumed that relief of residual stresses in heat-treated parts will occur by the shape changes which have been described above; however, it has been demonstrated that elastic residual stresses may still be present in heat-treated parts that have been tempered and theoretically should be stress free. By a very straightforward and simple application of the backreflection X-ray diffraction method for residual-stress determination, a very striking relationship has been demonstrated between the shape (angular) distortion of both A2 tool steel (air hardening) and O1 tool steel (oil hardening) and the residualstress pattern of these steels. Conversely, one could presumably utilize residualstress data at changes in cross section to estimate semiquantitatively the amount of shape distortion which occurs in rather complex parts.

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