Numerical modelling and physical simulation of the softening behaviour of hot work tool steels during thermal fatigue

2004 ◽  
Vol 120 ◽  
pp. 649-656
Author(s):  
I. Siller ◽  
W. Waldhauser ◽  
R. Ebner
Keyword(s):  
Thermal Fatigue ◽  
Physical Simulation ◽  
Fatigue Testing ◽  
Fatigue Behaviour ◽  
Fatigue Tests ◽  
Tool Steels ◽  
Chaboche Model ◽  
Different Temperatures ◽  
Pull Tests ◽  
Hot Work Tool Steels

Fatigue due to thermal cycling is one of the main reasons for the damage of tools used in die casting processes. In order to investigate the thermal fatigue behaviour of tool steels a thermal fatigue testing facility was designed and built up. For better understanding of the mechanisms of thermal fatigue finite element-simulations were carried out. To specify the cyclic material behaviour push-pull-tests at different temperatures were performed. The Chaboche-model was used to describe the kinematic material response. Isotropic softening is also taken into account. Depending on the arising accumulated plastic strain stable cyclic deformation or continuous softening occurs. The results are consistent with the accomplished thermal fatigue tests on different hot work tool steels.

Thermal-fatigue behaviour of hot-work tool steels

1981 ◽  
Vol 8 (1) ◽  
pp. 376-381 ◽  
Author(s):  
L.-Å. Norström ◽  
M. Svensson ◽  
N. Öhrberg
Keyword(s):  
Thermal Fatigue ◽  
Fatigue Behaviour ◽  
Tool Steels ◽  
Hot Work Tool Steels

Fatigue Testing of Polymeric Hollow Fibre Heat Transfer Surfaces by Pulsating Pressure Loads

2016 ◽  
Vol 821 ◽  
pp. 3-9 ◽  
Author(s):  
Tereza Brožová ◽  
Tomáš Luks ◽  
Ilya Astrouski ◽  
Miroslav Raudenský
Keyword(s):  
Heat Transfer ◽  
Fatigue Testing ◽  
Fatigue Loading ◽  
Hollow Fibre ◽  
Fatigue Tests ◽  
Outer Diameter ◽  
Hollow Fibres ◽  
Different Temperatures ◽  
Hot Bath ◽  
Number Of Cycles

This article deals with fatigue tests of polymeric hollow fibre heat transfer surfaces. The hollow fibres have an outer diameter between 0.5-0.8 mm and wall thickness 10 % of the outer diameter. These plastic heat transfer surfaces have some limitations but also many benefits. One of the limitations is the durability of plastic under fatigue loading. The heat transfer surfaces were subjected to pulsating pressure loads under different conditions (level of pressure, ambient temperature, number of cycles). Firstly, only an internal hydraulic pulsating load was applied and the behaviour of the hollow fibres was observed, focusing especially on the presence of leaks, ruptures, etc.Then, other conditions of operations were added. The heat transfer surfaces were immersed in a hot bath and loaded by internal pulsating pressure and high temperature simultaneously. Testing under different temperatures is important because the temperature significantly affects the material properties. The presence of leaks, ruptures and other possible damage was monitored as with previous tests.

The Thermo-Mechanical Behaviour of Alloy 600 and Alloy 82 Materials

2018 ◽  
Author(s):  
Vasileios Akrivos ◽  
Mike C. Smith
Keyword(s):  
Weld Metal ◽  
Low Cycle Fatigue ◽  
Mechanical Tests ◽  
Fatigue Tests ◽  
Parent Material ◽  
Model Parameters ◽  
Alloy 600 ◽  
Cycle Fatigue ◽  
Chaboche Model ◽  
Different Temperatures

Isothermal uniaxial low cycle fatigue tests have been performed at two different total strain ranges (1.5% and 2.5%) and at different temperatures (20, 200, 400 and 600°C) for Alloy 600 and Inconel 82 materials. The materials hardening behaviour has been fitted using the Lemaitre Chaboche formulations using different fitting strategies. Thermo mechanical tests have been performed using a Gleeble machine on both parent material and weld metal. In these tests thermal cycles were applied to a constrained specimen simulating the welding conditions in both the heat affected zone and a weld bead when subsequent beads are deposited alongside. The tests were modelled using two different FE codes, namely Code_Aster and Abaqus. This allowed the validation of the Lemaitre-Chaboche model parameters when the material is subjected to realistic thermo-mechanical cycles. Simulations were conducted using both annealing and/or viscous recovery features to examine their impact on the predicted response.

Elevated Temperature Fatigue Fracture Behaviour of Aluminium Alloy Subjected to Spectrum Loadings

2012 ◽  
Vol 165 ◽  
pp. 219-223
Author(s):  
K.A. Zakaria ◽  
S. Abdullah ◽  
Mariyam Jameelah Ghazali ◽  
C.H. Azhari
Keyword(s):  
Aluminium Alloy ◽  
Fatigue Fracture ◽  
Elevated Temperatures ◽  
Fatigue Testing ◽  
Fracture Behaviour ◽  
Testing Machine ◽  
Fatigue Behaviour ◽  
Fatigue Tests ◽  
Engine Mount ◽  
Load Sequence

This paper discusses the fatigue fracture behaviour of aluminium alloy AA6061-T6 under spectrum loadings at room and elevated temperatures. The load sequence can have a very significant effect in fatigue lives and normally the fatigue strength of material decrease with increasing temperature. In this study, variable amplitude loading (VAL) signal was obtained from the engine mount bracket of an automobile in a normal driving condition. Constant amplitude loading (CAL), high to low and low to high spectrum loadings were then derived from the VAL obtained from the data capturing process to study the fatigue behaviour that subjected to spectrum loadings at the room and elevated temperatures. The fatigue tests were performed according to an ASTM E466 standard using a servo-hydraulic fatigue testing machine. Fatigue fracture surfaces were then sectioned and inspected by employing a high magnification microscope. Results indicated that fracture surface behaviours of specimens were influenced significantly by the load sequence and temperatures, which can be related to the fatigue lives of aluminium alloy under spectrum loadings.

scholarly journals The Influence of Laser Surface Alloying on the Thermal Fatigue Resistance of Hot Work Tool Steels

2016 ◽  
Vol 61 (3) ◽  
pp. 1309-1314 ◽  
Author(s):  
E. Jonda ◽  
Z. Brytan ◽  
K. Labisz ◽  
A. Drygała
Keyword(s):  
Surface Layer ◽  
Fatigue Resistance ◽  
Thermal Fatigue ◽  
Laser Surface ◽  
Strengthening Effect ◽  
Surface Alloying ◽  
Tool Steels ◽  
Laser Surface Alloying ◽  
Thermal Fatigue Resistance ◽  
Hot Work Tool Steels

Abstract The paper presents results of the effect of laser surface remelting and alloying by carbides powders of NbC, TaC, TiC, VC and WC on the structure and thermal fatigue resistance of the surface layer of hot work tool steels X40CrMoV5-1 and 32CrMoV12-28. The laser surface alloying and remelting treatments was performed using a high power diode laser (HPDL ROFIN SINAR DL 020). In order to investigate the effect of applied laser treatments and used alloying powders on the microstructure and thermal fatigue resistance of processed surface layer of hot work tool steels, the microstructure evaluation by light microscopy, hardness test, and dedicated thermal fatigue resistance test were performed. The best results regarding fatigue cracks inhibition was obtained when the surface of hot work tool steels was alloyed with TiC and VC carbides at the laser beam power of 2.0 and 2.3 kW. The grain refinement effect of laser remelting has a lower impact on the thermal crack inhibition, than a strong strengthening effect of matrix saturation in alloying elements and precipitation of fine carbides in the steel matrix.

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