Modified Low Cycle Method as a New Criterion for a Life Fatigue Assessment in Foundry Industry

2013 ◽  
Vol 58 (3) ◽  
pp. 877-881
Author(s):  
M. Maj ◽  
K. Pietrzak ◽  
J. Piekło
Keyword(s):  
Fatigue Test ◽  
Low Cycle Fatigue ◽  
Cast Steel ◽  
Testing Machine ◽  
Mechanical Tests ◽  
Fatigue Tests ◽  
The Novel ◽  
Cycle Fatigue ◽  
Novel Method ◽  
New Criterion

Abstract The study describes the investigations of fatigue life carried out on selected grades of the G20Mn5 cast steel by two methods, i.e. the standard low-cycle fatigue test (LCF test) and modified low-cycle fatigue test (MLCF). The aim of these investigations was to verify the reliability of tests conducted by the novel method of MLCF [1, 2, 3]. Table 1 shows the results of mechanical tests carried out in accordance with the MLCF methodology on the G20Mn5 cast steel, while Figures 1a-b and 2 show the selected σ = f (ε) curves. Similar studies were carried out for the Mn-Ni cast steel [4]. Low-cycle fatigue tests (LCF) were carried out on an MTS 810 testing machine with control of force exerted on specimens whose dimensions were specified in [2].

Low Cycle Fatigue Test of Lead Free Solders Using Small Sized Specimen

2017 ◽  
Vol 734 ◽  
pp. 194-201 ◽  
Author(s):  
Yutaka Konishi ◽  
Takamoto Itoh ◽  
Masao Sakane ◽  
Fumio Ogawa ◽  
Hideyuki Kanayama
Keyword(s):  
Fatigue Testing ◽  
Low Cycle Fatigue ◽  
Testing Machine ◽  
Strain Range ◽  
Fatigue Tests ◽  
Lead Free ◽  
Cycle Fatigue ◽  
Bulk Specimen ◽  
Free Solder ◽  
Lead Free Solders

This paper investigates the fatigue results in low cycle fatigue region obtained from a miniaturized specimen having a 6mm gage length, 3mm diameter and 55mm total length. Fatigue tests were performed for two type lead-free solders using horizontal-type electrical servo hydraulic push-pull fatigue testing machine. Materials employed were Sn-3.0Ag-0.5Cu and Sn-5Sb. The results from Sn-3.0Ag-0.5Cu were compared with those obtained using a bulk specimen in a previous study. Relationship between strain range and number of cycles to failure of the small-sized specimen agreed with those of the bulk specimens. The testing techniques are applicable to Sn-5Sb following the Manson-Coffin law. These results confirm that the testing technique proposed here, using small-sized specimen, is suitable to get fruitful fatigue data for lead-free solder compounds.

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.

Low Cycle Fatigue Behaviour of GX12CrMoVNbN9 -1 Cast Steel at Room Temperature

2011 ◽  
Vol 291-294 ◽  
pp. 1106-1109 ◽  
Author(s):  
Grzegorz Golański ◽  
Krzysztof Werner ◽  
Stanisław Mroziński
Keyword(s):  
Heat Treatment ◽  
Room Temperature ◽  
Low Cycle Fatigue ◽  
Cast Steel ◽  
Fatigue Behaviour ◽  
Fatigue Tests ◽  
Total Strain Amplitude ◽  
Cycle Fatigue ◽  
Number Of Cycles ◽  
Stabilization Period

The report treats of the low cycle fatigue (LCF) behaviour of GX12CrMoVNbN9-1 (GP91) cast steel after heat treatment (1040°C/12h/oil + 760°C/12h/air + 750°C/8h/furnace). Fatigue tests were carried out at room temperature for five levels of the controlled total strain amplitude εac = 0.25, 0.30, 0.35, 0.50 and 0.60 %. The research performed within the scope of LCF has shown in general that the investigated cast steel was subject to strong cyclic weakening, revealing no stabilization period at the same time. At the final stage of fatigue there was quick weakening of the material which proceeded till its destruction. The growth of amplitude εac resulted in reducing the number of cycles till the destruction stage.

True and Nominal Stress during Low Cycle Fatigue Tests of Metals

2016 ◽  
Vol 250 ◽  
pp. 139-144
Author(s):  
Stanislaw Mrozinski
Keyword(s):  
Comparative Analysis ◽  
Strain Energy ◽  
Low Cycle Fatigue ◽  
True Strain ◽  
Cast Steel ◽  
Fatigue Tests ◽  
Cycle Fatigue ◽  
Nominal Strain ◽  
True Stresses ◽  
Transverse Strains

In this paper results of P91 cast steel after static and fatigue tests were presented. During the tests longitudinal and transverse strains of the specimen were measured. Basing on the results a comparative analysis of nominal stresses σn,true stresses σrz, nominal strain energy ΔWpl (n) and true strain energy ΔWpl (n) was carried out. It was stated that differences between determined paramters rise with increasing strain.

Microstructural Aspects of Low Cycle Fatigue of Aged GX12CrMoVNbN9-1 Cast Steel

2013 ◽  
Vol 592-593 ◽  
pp. 708-711
Author(s):  
Stanisław Mroziński ◽  
Grzegorz Golański ◽  
Krzysztof Werner
Keyword(s):  
Low Cycle Fatigue ◽  
Cast Steel ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Fatigue Tests ◽  
Total Strain Amplitude ◽  
Cycle Fatigue ◽  
Transmission Electron Microscopy Study ◽  
Transmission Electron ◽  
The Matrix

The paper presents the results of research on the changes in microstructure of GX12CrMoVNbN9-1 cast steel subject to aging at the temperature of 600°C and holding time of 8000 hours, followed by low-cycle fatigue. The characteristics of the microstructure of the examined cast steel after ageing and low-cycle fatigue was described using transmission electron microscopy (study of the dislocation microstructure) and morphology of precipitations. It has been shown that low cycle fatigue leads to the matrix softening as a result of the processes of recovery, polygonization and repolygonization. Moreover, the processes of precipitation of Laves phase and coagulation of M23C6 carbides were observed in the microstructure. Intensity of these processes depended not only on the temperature of fatigue tests, but also on the level of total strain amplitude εac.

4008 Evaluation of Cyclic Softening Behavior of Cr-Mo-V Cast Steel by Low Cycle Fatigue Test

2006 ◽  
Vol 2006.1 (0) ◽  
pp. 945-946
Author(s):  
Akihiro Kanaya ◽  
Junichi Kusumoto ◽  
Hiroyuki Hayakawa ◽  
Kouji Nagazumi
Keyword(s):  
Fatigue Test ◽  
Low Cycle Fatigue ◽  
Cast Steel ◽  
Cyclic Softening ◽  
Cycle Fatigue ◽  
Softening Behavior

Evaluation of Continuous Low-Cycle Fatigue Behaviour of High Temperature P122 Boiler Material

2002 ◽  
Author(s):  
John Pumwa ◽  
Soo Woo Nam
Keyword(s):  
High Temperature ◽  
Fracture Mode ◽  
Low Cycle Fatigue ◽  
Testing Machine ◽  
Fatigue Behaviour ◽  
Fatigue Tests ◽  
Transgranular Fracture ◽  
Cycle Fatigue ◽  
Boiler Material ◽  
As Stress

The complex thermal-mechanical loading of power-generating plant components usually comprises of creep, high-cycle and low-cycle fatigue which are thermally induced by start-ups, load changes and shut-downs, producing instationary temperature gradients and hence creating strain as well as stress fields. In order to select the correct materials for these hostile environmental conditions, it is vitally important to understand the behaviour of mechanical properties of these materials. This paper reports the results of Low-cycle fatigue tests of P122 (HCM12A or 12Cr-1.8W-1.5Cu) high temperature boiler material, which is one of the latest developed materials for high temperature environments. The tests were conducted at temperatures ranging from 550°C to 700 °C at 50°C intervals with strain ranges of ±1.5 to ±3.0% at 0.5% intervals using a closed-loop hydraulic Instron material testing machine with a servo hydraulic controller. The results confirm that P122 is comparable to conventional high temperature steels. Moreover, the fracture mode assessments strongly revealed a ductile transgranular fracture mode.

Proposition of Low-Cycle Fatigue Test Termination Criterion Based on Specimen Temperature Change

2016 ◽  
Vol 250 ◽  
pp. 114-119
Author(s):  
Adam Lipski ◽  
Zbigniew Lis
Keyword(s):  
Fatigue Test ◽  
Temperature Change ◽  
Low Cycle Fatigue ◽  
Cast Steel ◽  
Total Strain Amplitude ◽  
Cycle Fatigue ◽  
Good Compliance ◽  
Axial Tension ◽  
Specimen Temperature ◽  
Termination Criterion

This paper presents proposition of the low-cycle fatigue test termination criterion based on specimen temperature change. The tests were performed using specimens made of G-X12CrMoVNbN9-1 (GP91) martensitic cast steel under axial tension-compression conditions with strain controlled at the total strain amplitude levels amounting to εac = 0.25%, 0.5% and 0.6%. Very good compliance of the proposed criterion with the criterion used so far was obtained. The discrepancy for the tested material has not exceeded 2% in the εac stress range not exceeding 0.5%.

Low Cycle Fatigue of GX12CrMoVNbN9 -1 Cast Steel at 600°C Temperature

2011 ◽  
Vol 396-398 ◽  
pp. 326-329 ◽  
Author(s):  
Grzegorz Golański ◽  
Krzysztof Werner ◽  
Stanisław Mroziński
Keyword(s):  
Heat Treatment ◽  
Fatigue Life ◽  
Low Cycle Fatigue ◽  
Cast Steel ◽  
Fatigue Tests ◽  
Total Strain ◽  
Cycle Fatigue ◽  
The Given ◽  
Cycles To Failure ◽  
Stabilization Period

The paper treats of the low cycle fatigue (LCF) behaviour of GX12CrMoVNbN9-1 (GP91) cast steel after heat treatment. Fatigue tests at the temperature of 600oC within the scope of small amount of cycles to failure were carried out for five levels of controlled amplitude of total strain εac = 0.25, 0.30, 0.35, 0.50 and 0.60 %. The investigated cast steel within the scope of low cycle fatigue life reveals a three-stage course of changes in strength and strain. In the given scope of low cycle fatigue for GP91 cast steel, cyclic weakening was observed without the occurrence of stabilization period of its properties.

scholarly journals Characteristics of Non-Ferrous Metal Alloys as Determined by Low-Cycle Fatigue Test under Variable Loads

2014 ◽  
Vol 14 (1) ◽  
pp. 71-74 ◽  
Author(s):  
M. Maj ◽  
K. Pietrzak
Keyword(s):  
Fatigue Test ◽  
Low Cycle Fatigue ◽  
Ferrous Metal ◽  
Fatigue Tests ◽  
Metal Alloys ◽  
Fatigue Properties ◽  
Cycle Fatigue ◽  
Ferrous Alloys ◽  
Comparative Tests ◽  
Al 7075

Abstract The paper presents the results of comparative tests of the fatigue properties conducted on two non-ferrous alloys designated as Al 6082 and Al 7075 which, due to the satisfactory functional characteristics, are widely used as engineering materials. The fatigue tests were carried out using a proprietary, modified low cycle test (MLCF). Particular attention was paid to the fatigue strength exponent b and fatigue ductility exponent c. Based on the tests carried out, the results comprised within the range defined by the literature were obtained. These results prove a satisfactory sensitivity of the method applied, its efficiency, the possibility of conducting tests in a fully economical way and above all the reliability of the obtained results of the measurements. Thus, the thesis has been justified that the modified low cycle fatigue test (MLCF) can be recommended as a tool used in the development of alloy characteristics within the range of low-cycle variable loads

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