Influence of Single and Summary Deformation for the Change of Limit Stress in the Drawing Process Based on the Pelczynski Diagram

2016 ◽  
Vol 246 ◽  
pp. 183-188
Author(s):  
Dariusz Halaczek
Keyword(s):  
Yield Strength ◽  
Cold Deformation ◽  
Wire Drawing ◽  
Biaxial Compression ◽  
Uniaxial Tensile ◽  
Drawing Process ◽  
A Value ◽  
Plastic Forming ◽  
Limit Stress ◽  
Stress States

Limit stress diagram by Pelczyński was constructed in the coordinates σm - σH (σm - average stress for the process, σH - stress according to the Huber hypothesis) based on the hypothesis Huber - de Saint Venant and is consistent connection between the two hypotheses. This diagram allows for presentation the dangerous states of stresses for arbitrary stress state so plane and space (biaxial and triaxial). It also allows for the analysis of stress states occurring in various processes of plastic forming. To determine the state stresses occurring in the technological process starts from the components of the plastic deformation. In the case of a wire drawing process with a circular section in the inlet area of the die there is equality of deformation φ2 = φ3 and the equality of stress σ2 = σ3 (which is uniform biaxial compression), while in a outlet of the die there is a uniaxial tensile σ1, which cannot achieve a value equal to σp (yield strength), since in this case the wire could be deformed outside the die.The aim of this study was to construct the Pelczynski diagram in such a way to show on the example of brass wire M63, the course of the stresses in the drawing process.The research program included:- Realization of the drawing processes in order to obtain samples of varying degrees strengthening,- Determination on the basis of tensile strength the properties Rm, Rp0,2 and cohesive strength of R0 for varying degrees of strengthening,- Determine the influence of cold deformation for the course of curve of the yield strength,- Constructing a diagram of drawing process on a background of the diagram of yield strength in this process.

Hot and Cold Deformation Behaviors and Microstructure Evolutions of Mn18Cr18N Austenitic Stainless Steel with High-Nitrogen

2021 ◽  
Vol 1016 ◽  
pp. 325-331
Author(s):  
Hui Qin Chen ◽  
Ji Hong Tian ◽  
Fei Li ◽  
Feng Ming Qin ◽  
Wen Wu He
Keyword(s):  
Flow Stress ◽  
Dynamic Recrystallization ◽  
Microstructure Evolution ◽  
Cold Deformation ◽  
Maximum Tensile Stress ◽  
Biaxial Compression ◽  
Uniaxial Tensile ◽  
Strain Rates ◽  
Dislocation Mechanism ◽  
Cross Sectional

Hot and cold deformation behavious and microstructure evolutions of Mn18Cr18N were investigated by thermo-mechanical modeling experiments and microstructure analysis. The results show that hot deformation flow stress curves characterized by the same work hardening and subsequent stress softening varied with temperatures and strain rates for both of as-cast and as-forged samples. And flow stresses are sensitive to strain rate. At strain rates lower than 0.01s-1, the flow stresses are lower, and microstructure evolution controlled by dislocation mechanism dynamic recrystallization; At strain rates higher than 0.1s-1, the flow stresses are higher, and microstructure evolution controlled by twinning mechanism dynamic recrystallization. But the dynamic recrystallzed fraction of the as-cast sample was much less than that of the as-forged sample. For cold deformation, the simple uniaxial tensile sample shows that the monotone increasing flow stress curve and monotone decreasing work-hanrdening rate. However, for the uniaxial and biaxial compression-tensile samples with different previous compression, the subsequent tensile yield stress, the maximum tensile stress, the reduction of cross sectional area and the elongation have extremums respectively at the previous compressive deformation of about 25%-30%. Microstructure evolution mechanisms during cold deformation were planar slipping and twinning.

scholarly journals Shape Analysis of the Elastic Deformation Region throughout the Axi-Symmetric Wire Drawing Process of ETP Grade Copper

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4713
Author(s):  
Paweł Strzępek ◽  
Andrzej Mamala ◽  
Małgorzata Zasadzińska ◽  
Grzegorz Kiesiewicz ◽  
Tadeusz Antoni Knych
Keyword(s):  
Elastic Deformation ◽  
Metal Flow ◽  
Wire Drawing ◽  
Uniaxial Tensile ◽  
Geometrical Parameters ◽  
Drawing Process ◽  
Strength Parameters ◽  
Deformation Region ◽  
Drawing Die ◽  
Plastic Deformation Region

The wire drawing process is commonly perceived as one of the best studied metal forming processes in almost every aspect; however, when considering elastic deformation, researchers usually focus on the uniaxial tensile forces after the material exits the drawing die and not the elastic deformation region before entering the drawing die, even though it may have a significant impact on the strength parameters and the nature of metal flow inside the drawing die. The aim of this research is to theoretically and experimentally identify the deformation in the elastic region and to further link the shape of this region and the values of stress occurring in it with the geometrical parameters of the drawing process and assess its impact on its strength parameters. In order to achieve the assumed goals, numerical analyses using the finite element method and experimental research on the drawing process in laboratory conditions were carried out using Vickers hardness tests and resistance strain gauges measuring deformation in stationary and non-stationary conditions. The obtained results indicate that the shape and the extent of the region of elastic deformations generated in the material before the plastic deformation region during the drawing process depends on the applied deformation coefficient and stationarity of the process.

Experimental Investigation of Ti-6Al-4V with a Biaxial Tensile Test Setup at Elevated Temperature

2014 ◽  
Vol 622-623 ◽  
pp. 273-278 ◽  
Author(s):  
Marion Merklein ◽  
Sebastian Suttner ◽  
Adam Schaub
Keyword(s):  
Elevated Temperature ◽  
Elevated Temperatures ◽  
Tensile Tests ◽  
Advanced Materials ◽  
Uniaxial Tensile ◽  
Plastic Yielding ◽  
Characterization Methods ◽  
Specific Strength ◽  
Biaxial Tensile ◽  
Stress States

The requirement for products to reduce weight while maintaining strength is a major challenge to the development of new advanced materials. Especially in the field of human medicine or aviation and aeronautics new materials are needed to satisfy increasing demands. Therefore the titanium alloy Ti-6Al-4V with its high specific strength and an outstanding corrosion resistance is used for high and reliable performance in sheet metal forming processes as well as in medical applications. Due to a meaningful and accurate numerical process design and to improve the prediction accuracy of the numerical model, advanced material characterization methods are required. To expand the formability and to skillfully use the advantage of Ti-6Al-4V, forming processes are performed at elevated temperatures. Thus the investigation of plastic yielding at different stress states and at an elevated temperature of 400°C is presented in this paper. For this reason biaxial tensile tests with a cruciform shaped specimen are realized at 400°C in addition to uniaxial tensile tests. Moreover the beginning of plastic yielding is analyzed in the first quadrant of the stress space with regard to complex material modeling.

Effect of operating parameters on functional fatigue characteristics of an Ni-Ti shape memory alloy on partial thermomechanical cycling

2022 ◽  
pp. 1045389X2110722
Author(s):  
Swaminathan Ganesan ◽  
Sampath Vedamanickam
Keyword(s):  
Yield Strength ◽  
Applied Stress ◽  
Stress Level ◽  
Crack Nucleation ◽  
Maximum Temperature ◽  
Thermomechanical Cycling ◽  
Permanent Strain ◽  
A Value ◽  
The Stability ◽  
Cycle Temperature

In this study, the influence of upper cycle temperature (maximum temperature in a cycle) and the magnitude of applied stress on the functional properties of an SMA during partial thermomechanical cycling has been studied. A near-equiatomic NiTi SMA was chosen and tested under different upper cycle temperatures (between martensite finish (Mf) and austenite finish (Af) temperatures) and stress level (below and above the yield strength of the martensite). The upper cycle temperature was varied by controlling the magnitude of the current supply. The results show that a raise in the upper cycle temperature causes the permanent strain to increase and also lowers the stability. However, decreasing the stress imposed to a value lower than the yield strength of the martensite improves cyclic stability. The upper cycle temperature was found to influence the crack nucleation, whereas the applied stress level the crack propagation during partial thermomechanical cycling of SMAs. Therefore, decreasing the upper cycle temperature as well as the magnitude of stress applied to lower than the yield stress of martensite have been found to be suitable strategies for increasing the lifespan of SMA-based actuators during partial thermomechanical cycling.

Correlation among Microstructure, Texture, and Properties along the Thickness Direction in As-Hot-Rolled and As-Solution-Quenched Al7055 Thick Plates

2021 ◽  
Vol 1026 ◽  
pp. 65-73
Author(s):  
Kai Zhu ◽  
Hong Wei Yan
Keyword(s):  
Mechanical Properties ◽  
Yield Strength ◽  
Tensile Tests ◽  
Rolled Plate ◽  
Uniaxial Tensile ◽  
Thickness Direction ◽  
Electron Backscattered Diffraction ◽  
Thick Plates ◽  
Aluminum Plates ◽  
Hot Rolled

Both microstructure inhomogeneity and mechanical property diversity along the thickness direction in rolled thick aluminum plates have been considered to have a remarkable impact on the performance and properties of the products made from the plates. In this study, scanning electron microscopy (SEM) and electron backscattered diffraction (EBSD) characterizations of microstructure and texture types along the thickness directions of Al7055 thick plate specimens prepared using two conditions, hot-rolling and solution-quenching, were performed. To examine the mechanical properties, uniaxial tensile tests were also carried out on specimens machined from both types of thick plates, using a layered strategy along the thickness direction. The results indicate that both the microstructure and mechanical properties are inhomogeneous under the two conditions. Furthermore, it is evident that there is a hereditary relationship between the mechanical properties of the two plates—areas with higher yield strength in the as-hot-rolled plate correspond to areas with the higher yield strength in the as-solution-quenched plate

Deformation Law of Cold Drawing Process of High Strength Bridge Cable Steel

2021 ◽  
Vol 1035 ◽  
pp. 801-807
Author(s):  
Xiao Lei Yin ◽  
Jian Cheng ◽  
Gang Zhao
Keyword(s):  
Strain Path ◽  
High Strength ◽  
Cold Drawing ◽  
Wire Drawing ◽  
Radial Deformation ◽  
Steel Bridge ◽  
Drawing Process ◽  
Single Pass ◽  
Potential Relationship ◽  
The Wire

High-strength cable-steel bridge is the “lifeline” of steel structure bridges, which requires high comprehensive mechanical properties, and cold-drawing is the most important process to produce high-strength cable-steel bridge. Therefore, through the ABAQUS platform, a bridge wire drawing model was established, and the simulation analysis on the process of stress strain law and strain path trends for high-strength bridge steel wire from Φ 12.65 mm by seven cold-drawing to Φ 6.90 mm was conducted. The simulation results show that the wire drawing the heart of the main axial deformation, surface and sub-surface of the main axial and radial deformation occurred, with the increase in the number of drawing the road, the overall deformation of the wire was also more obvious non-uniformity. In the single-pass drawing process, the change in the potential relationship of each layer of material was small, and multiple inflection points appeared in the strain path diagram; the change in the seven-pass potential relationship was more drastic, which can basically be regarded as a simple superposition of multiple single-pass pulls.

Anisotropy in Compression Creep-Ageing Behavior of 2219-T3 Aluminum Alloy

2021 ◽  
Vol 315 ◽  
pp. 31-36
Author(s):  
Xue Ying Chen ◽  
Li Hua Zhan ◽  
Hai Long Liao ◽  
Yuan Gao
Keyword(s):  
Aluminum Alloy ◽  
Yield Strength ◽  
Applied Stress ◽  
Material Properties ◽  
Rolling Direction ◽  
Deformation Texture ◽  
Compression Creep ◽  
Stress States ◽  
And Performance ◽  
Distribution Of Stress

Creep age forming technology (CAF) has been widely used to manufacture large integral panels in aerospace industry. However, due to the bending of the sheet metal, the stress states usually changes along the thickness direction during the CAF process, resulting in a complex distribution of stress. In addition, deformation texture is introduced when the sheet has a large pre-deformation, which also greatly affects the shape and performance of the component after aging. In this paper, the anisotropy in compression creep-ageing behavior of 2219-T3 aluminum alloy was studied. It was found that there is obvious anisotropy of compressive creep strains, the creep strain is the largest when the applied stress is along the rolling direction (RD) and the smallest when the applied stress is along the transverse direction (TD). The results of room temperature (25 ° C) and high temperature (165 ° C) tensile property test shows that the as-received material properties has obvious in-planar anisotropy, and the yield strength in the RD is the largest, but the 45° and TD are basically the same. Interestingly, the anisotropy of yield strength after SFA and compressive stress creep aging has basically disappeared, that is,the material properties tended to be isotropic after ageing.

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