A Load Calibration Technique for Use on Large Industrial Presses and Small Testing Machines

1975 ◽  
Vol 97 (3) ◽  
pp. 951-956
Author(s):  
V. DePierre ◽  
S. O. Davis ◽  
F. J. Gurney
Keyword(s):  
Flow Stress ◽  
Small Ring ◽  
Test Machine ◽  
Ring Specimen ◽  
Calibration Technique ◽  
Extrusion Press ◽  
Full Capacity ◽  
Ring Cell ◽  
Hydraulic Extrusion ◽  
Geometric Changes

A load calibration technique based on the plastic deformation of a ring specimen is described. The method is applicable to any size press at loads up to full capacity. The method consists of determining the true flow stress of a heat of material by compression of small ring specimens on a calibrated test machine and treating the geometric change of the ring mathematically. Larger rings from the same heat of material are then deformed in large industrial presses or smaller testing machines which are to be calibrated. The geometric changes in the ring specimen and the previously determined flow stress are treated by the same mathematical analysis to determine the deformation pressure and thus the deformation load. A comparison is made of the calibration from the ring cell with other calibrations already determined on a mechanical crank press and a hydraulic extrusion press. The ring cell is shown to yield highly accurate load information.

scholarly journals The development of a novel technique for small ring specimen tensile testing

2019 ◽  
Vol 99 ◽  
pp. 131-139 ◽  
Author(s):  
J. Kazakeviciute ◽  
J.P. Rouse ◽  
D.S.A. De Focatiis ◽  
C.J. Hyde
Keyword(s):  
Tensile Testing ◽  
Small Ring ◽  
Ring Specimen ◽  
Novel Technique

scholarly journals The development of a novel small ring specimen tensile testing technique

2018 ◽  
Vol 1 (S1) ◽  
pp. 29
Author(s):  
J. Kazakeviciute ◽  
J.P. Rouse ◽  
C.J. Hyde
Keyword(s):  
Tensile Testing ◽  
Small Ring ◽  
Ring Specimen ◽  
Testing Technique

scholarly journals Constitutive Model of 30CrMoA Steel with Strain Correction

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1214
Author(s):  
Song Zhang ◽  
Xuedao Shu ◽  
Jitai Wang ◽  
Yingxiang Xia
Keyword(s):  
Flow Stress ◽  
Constitutive Model ◽  
High Speed ◽  
Strain Curve ◽  
Material Constant ◽  
Test Machine ◽  
Experimental Stress ◽  
High Speed Train ◽  
Stress Strain Curve ◽  
Stress Strain

It is necessary to establish a constitutive model of 30CrMoA steel to optimize the forming shape and mechanical properties of high-speed train axles. The experimental stress–strain curve of 30CrMoA steel was obtained by an isothermal compression test on a Gleeble-3500 thermal simulation test machine under temperature of 1273~1423 K and strain rate of 0.01~10 s−1. Considering the effect of strain on the material constant, an empirical constitutive model was proposed with strain correction for 30CrMoA steel. In addition, the material constant in the constitutive model is determined by linear regression analysis of the experimental stress–strain curve. Comparing the theoretical value and experimental value of flow stress, the correlation R is 0.9828 and the average relative error (ARRE) is 4.652%. The constitutive model of 30CrMoA steel with strain correction can reasonably predict the flow stress under various conditions. The results provide an effective numerical tool for further study on accurate near-net forming of high-speed train axles.

Characterization of Hot Deformation Behavior of Ti-4.5Al-3V-2Mo-2Fe Titanium Alloy

2016 ◽  
Vol 849 ◽  
pp. 309-316 ◽  
Author(s):  
Li Wei Zhu ◽  
Xin Nan Wang ◽  
Yue Fei ◽  
Jing Li ◽  
Zhi Shou Zhu
Keyword(s):  
Titanium Alloy ◽  
Flow Stress ◽  
Strain Rate ◽  
Hot Deformation ◽  
Deformation Behavior ◽  
Constant Strain Rate ◽  
Test Machine ◽  
Peak Efficiency ◽  
Hot Deformation Behavior ◽  
Dynamic Materials

The hot deformation behavior of Ti-4.5Al-3V-2Mo-2Fe (SP-700) titanium alloy in the temperature range of 650°C~950°C and constant strain rate of 0.01, 0.1, 1 and 10s-1 has been investigated by hot compressive testing on the Gleeble-1500D thermal simulation test machine. The experimental results indicated that the hot deformation behavior of SP-700 alloy was sensitive to the deformation temperature and strain rate. The peak flow stress decreased with the increase of temperature and the decrease of strain rate. The flow curves characteristic under different deformation parameters show significant different. Analysis of the flow stress dependence on strain rate and temperature gives a stress exponent of n as 4.8235 and a deformation activation energy of Q as 410kJ/mol. Based on the dynamic materials model, the processing map is generated, which shows that the most peak efficiency domain appears at the temperature of 725°C~775°C and the strain rate of 0.001 s-1~0.003s-1 with a peak efficiency of 45% at about 750°C/0.01s-1.

scholarly journals RESEARCH ON MATERIAL FLOW-STRESS BEHAVIOR AND THE DIE-FORGING PROCESS FOR FORGED-STEEL BRAKE DISCS FOR HIGH-SPEED TRAINS

2021 ◽  
Vol 55 (6) ◽  
Author(s):  
Zhenhong Li ◽  
Chenxing Zhang ◽  
Chenyu Wang ◽  
Yingna Huang
Keyword(s):  
Flow Stress ◽  
Process Parameters ◽  
High Speed ◽  
Brake Disc ◽  
Test Machine ◽  
Forming Process ◽  
Finite Element Software ◽  
Die Forging ◽  
Brake Discs ◽  
High Speed Trains

Due to the large size and complicated features, the brake discs of high-speed trains are difficult to forge, so a reasonable design of the process and the die parameter are prerequisites for successful forming. The flow stress of 23CrNiMoV, a forged-steel brake disc material for high-speed trains, was investigated by a uniaxial compression experiment on a Gleeble 1500 test machine. Based on the obtained flow-stress data, a series of numerical simulation analyses of the die forging of high-speed-train brake discs were carried out by using finite-element software. The effects of forging temperature, flash groove parameters and forming speed on the flow filling, forming load and temperature change of metal during die forging were studied. The simulation results were optimized and better process parameters were obtained. Based on the obtained process parameters, the simulation of the forming process was completed and a better forming quality was obtained.

Hot Compressive Behavior of Ti-3.0Al-3.7Cr-2.0Fe Titanium Alloy at Different Strain Rates

2012 ◽  
Vol 560-561 ◽  
pp. 1072-1077
Author(s):  
Guo Wang ◽  
Song Xiao Hui ◽  
Wen Jun Ye
Keyword(s):  
Titanium Alloy ◽  
Flow Stress ◽  
Strain Rate ◽  
Early Stage ◽  
True Strain ◽  
Stable State ◽  
Constitutive Relationship ◽  
Test Machine ◽  
Strain Rates ◽  
Temperature Range

The characteristics of hot compression deformation of Ti-3.0Al-3.7Cr-2.0Fe titanium alloy have been studied by Gleeble−1500D thermal simulated test machine in the strain rates range 0.01～10s−1 and temperature range 800～950°C. The true stress-true strain curves show that the peak flow stress decrease with increase temperature and decrease strain rate. At the temperature range in the article, there is a distinct peak in the flow stress in the early stage deformation followed by a stable state at high strains. The variation of flow stress with temperature and strain rate follows the standard kinetic rate equation and the apparent activation energy is estimated to be about 214.22KJ•mol-1. The constitutive relationship of Ti-3.0Al-3.7Cr-2.0Fe alloy is obtained on the base of Arrhenius equation at the experimental conditions.

Dynamic Recrystallization Behavior of Pure Titanium

2014 ◽  
Vol 852 ◽  
pp. 66-70 ◽  
Author(s):  
Juan Hua Su ◽  
Ya Wei Han ◽  
Feng Zhang Ren ◽  
Zhi Qiang Chen
Keyword(s):  
Flow Stress ◽  
Dynamic Recrystallization ◽  
Strain Rate ◽  
True Strain ◽  
Pure Titanium ◽  
Avrami Equation ◽  
Test Machine ◽  
Commercially Pure Titanium ◽  
Compression Tests ◽  
Commercially Pure

The dynamic recrystallization of commercially pure titanium was investigated by compression tests on Gleeble-1500D thermal simulation test machine at temperature of 700950 °C and strain rate of 0. 015 s1. The total compression deformation is 0.7(true strain). The kinetics of dynamic recrystallization of commercially pure titanium at 950 °C was modeled by Avrami equation. The results show that the dynamic recovery and recrystallization obviously occur during compression. The flow stress increases to a peak value and gradually decreases to a steady state. The flow stress is decreased with the increase of deformation temperature and it is increased with the increase of strain rate. The Avrami kinetics model of dynamic recrystallization of commercially pure titanium at 950 °C is obtained .

Dislocation structures around SiO2 Particles in aged Cu-Cr-SiO2

1978 ◽  
Vol 36 (1) ◽  
pp. 594-595
Author(s):  
N.J. Long ◽  
M.H. Loretto ◽  
C.H. Lloyd
Keyword(s):  
Flow Stress ◽  
Single Crystals ◽  
Room Temperature ◽  
Thin Foil ◽  
Age Hardening ◽  
Dispersion Strengthening ◽  
Accurate Picture ◽  
The Matrix ◽  
Very High ◽  
Good Agreement

IntroductionThere have been several t.e.m. studies (1,2,3,4) of the dislocation arrangements in the matrix and around the particles in dispersion strengthened single crystals deformed in single slip. Good agreement has been obtained in general between the observed structures and the various theories for the flow stress and work hardening of this class of alloy. There has been though some difficulty in obtaining an accurate picture of these arrangements in the case when the obstacles are large (of the order of several 1000's Å). This is due to both the physical loss of dislocations from the thin foil in its preparation and to rearrangement of the structure on unloading and standing at room temperature under the influence of the very high localised stresses in the vicinity of the particles (2,3).This contribution presents part of a study of the Cu-Cr-SiO2 system where age hardening from the Cu-Cr and dispersion strengthening from Cu-Sio2 is combined.

Sign in / Sign up

Export Citation Format

Share Document