scholarly journals Relationship between Notch Strength Ratio and Strain Hardening Exponent for Tensile Specimens with Blunt Notches

2009 ◽  
Vol 75 (758) ◽  
pp. 1443-1445
Author(s):  
Makoto OHASHI
Keyword(s):  
Strain Hardening ◽  
Strain Hardening Exponent ◽  
Strength Ratio ◽  
Notch Strength

scholarly journals Effect of Bainite to Ferrite Yield Strength Ratio on the Deformability of Mesostructures for Ferrite/Bainite Dual-Phase Steels

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5352
Author(s):  
Gui-Ying Qiao ◽  
Zhong-Tao Zhao ◽  
Xian-Bo Shi ◽  
Yi-Yin Shan ◽  
Gu Yu ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Yield Strength ◽  
Strain Hardening ◽  
Pipeline Steel ◽  
Strain Hardening Exponent ◽  
Strength Increase ◽  
Dual Phase ◽  
Strength Ratio ◽  
Soft Phase ◽  
Deformation Compatibility

The strength and plasticity balance of F/B dual-phase X80 pipeline steels strongly depends on deformation compatibility between the soft phase of ferrite and the hard phase of bainite; thus, the tensile strength of ferrite and bainite, as non-negligible factors affecting the deformation compatibility, should be considered first. In this purely theoretical paper, an abstract representative volume elements (RVE) model was developed, based on the mesostructure of an F/B dual-phase X80 pipeline steel. The effect of the yield strength difference between bainite and ferrite on tensile properties and the strain hardening behaviors of the mesostructure was studied. The results show that deformation first occurs in ferrite, and strain and stress localize in ferrite prior to bainite. In the modified Crussard-Jaoul (C-J) analysis, as the yield strength ratio of bainite to ferrite (σy,B/σy,F) increases, the transition strain associated with the deformation transformation from ferrite soft phase deformation to uniform deformation of ferrite and bainite increases. Meanwhile, as the uncoordinated deformation of ferrite and bainite is enhanced, the strain localization factor (SLF) increases, especially the local strain concentration. Consequently, the yield, tensile strength, and yield ratio (yield strength/tensile strength) increase with the increase in σy,B/σy,F. Inversely, the strain hardening exponent and uniform elongation decrease.

Effect of Modulations on Yield Stress and Strain Hardening Exponent of Solution Treated Cu-Ti Alloys

1998 ◽  
Vol 38 (9) ◽  
pp. 1469-1474 ◽  
Author(s):  
S. Nagarjuna ◽  
M. Srinivas ◽  
K. Balasubramanian ◽  
D.S. Sarma
Keyword(s):  
Strain Hardening ◽  
Yield Stress ◽  
Strain Hardening Exponent ◽  
Stress And Strain ◽  
Ti Alloys ◽  
Solution Treated

Anomaly of the Work Hardening of Zn-Cu Single Crystals Oriented for Slip in Secondary Systems

2011 ◽  
Vol 56 (4) ◽  
pp. 1021-1027
Author(s):  
K. Pieła
Keyword(s):  
Strain Hardening ◽  
Single Crystals ◽  
Yield Stress ◽  
Work Hardening ◽  
Temperature Anomaly ◽  
Strain Hardening Exponent ◽  
Plastic Behavior ◽  
Thermal Dependence ◽  
Copper Addition ◽  
Secondary Systems

Anomaly of the Work Hardening of Zn-Cu Single Crystals Oriented for Slip in Secondary SystemsThe copper alloyed (up to 1.5%) zinc single crystals oriented for slip in non-basal systems (orientation close to < 1120 >) were subjected to compression test within a range of temperatures of 77-293K. It has been stated, that Zn-Cu crystals exhibit characteristic anomalies of the thermal dependence of yield stress and of the strain hardening exponent. Both of them are related to the change in type and sequence of active non-basal slip systems: pyramidal of the 1storder {1011} < 1123 > (Py-1) and pyramidal of the 2ndorder {1122} < 1123 > (Py-2). The temperature anomaly of the yield stress results from the change of the slip from Py-2 systems to simultaneous slip in the Py-2 and Py-1 (Py-2 + Py-1) systems, occurring in the preyielding stage. On the other hand, sequential activation of pyramidal systems taking place in advanced plastic stage (i.e. the first Py-2 and next Py-2 + Py-1 systems) is responsible for temperature anomaly of strain hardening exponent. Increase in copper addition favors the activity of Py-2 systems at the expense of Py-1 slip, what leads to a drastic differences in plastic behavior of zinc single crystals.

Influencing Factors for Improving Accuracy in Prediction of Stress Corrosion Crack Growth Rate in Boiling Water Reactor Operational Condition: Part 1—Prediction of SCC Growth Rate in Terms of Vickers Hardness

2010 ◽  
Author(s):  
Yoichi Takeda ◽  
Zhanpeng Lu ◽  
Takeshi Adachi ◽  
Qunjia Peng ◽  
Jiro Kuniya ◽  
...  
Keyword(s):  
Growth Rate ◽  
Stainless Steel ◽  
Yield Strength ◽  
Strain Hardening ◽  
Crack Growth ◽  
Vickers Hardness ◽  
316L Stainless Steel ◽  
Strain Hardening Exponent ◽  
Theoretical Formulation ◽  
Prediction Curve

It is known that stress corrosion cracking (SCC) found in the operational power plants show complex cracking behaviors and it’s resulted in complex crack shape e.g. crack branching and its uneven crack front. For the cracking near the weldment, this is due to crack penetrated along the complex distribution of residual stress and strain hardened area. In this investigation, in order to advance the accuracy for crack growth prediction with considering such complex fields, theoretical formulation for SCC growth was further modified. Hardness of the materials, which is a measureable parameter even in operational power plant, was focused on to reflect strain hardening of the component like heat affected zone of the weldments. The theoretical formulation for SCC growth has terms with yield strength of the material and strain hardening exponent to describe crack tip strain rate. Strain hardening was simulated by cross rolling with the range of 4 – 32% as thickness reduction. Correlation between yield strength, strain hardening exponent at 288°C and Vickers hardness was obtained by means of tensile tests and hardness tests on 316L stainless steel. It was observed that a monotonic increase in Vickers hardness and yield strength with degree of reduction in thickness worked by cross rolling. Relationship between Vickers hardness and yield strength was found to have linear correlation. Further confirmation was made by plotting the reported mechanical properties data in terms of Vickers hardness. In addition, linear relationship was found between yield strength and strain hardening exponent. These relationships were introduced into SCC theoretical formulation and a SCC growth rate prediction curve in terms of Vickers hardness was proposed. SCC crack growth evaluation tests with selected work hardened 316L stainless steel were performed in oxygenated pure water environment at 288°C to confirm the predictability of the formulation. The prediction curve had a good agreement with available literature data as well as obtained crack growth rates in the hardness range of 140–300HV which was likely expected one in weld HAZ.

scholarly journals THE ABILITY TO CLINCHING AS A FUNCTION OF MATERIAL HARDENING BEHAVIOR

2018 ◽  
Vol 24 (1) ◽  
pp. 58
Author(s):  
Tadeusz Balawender
Keyword(s):  
Strain Hardening ◽  
Strength Properties ◽  
Strain Hardening Exponent ◽  
Special Importance ◽  
Metallic Materials ◽  
Forming Process ◽  
Plastic Properties ◽  
Plastic Materials ◽  
Mechanical Clinching ◽  
Induced Defects

<p><span lang="EN-GB">Mechanical clinching can be used to joining different metallic materials. The only restriction are their plastic properties. However some plastic materials, with good ductility, do not conform strong clinch joint, e.g. materials, featured by high strain hardening phenomena are difficult to clinching and do not create durable clinch joint. In case of others materials with limited ductility clinch forming generates the process-induced defects such as cracks. So, there are material’s features which are very important for the clinch forming process and among them the strain hardening properties seem to be in special importance.</span></p><p><span lang="EN-GB"><span>                </span>The clinch joints of different materials with diversified plastic and strength properties<span>  </span>were tested. A single overlap clinch joints with one clinch bulge were realized in the tests. The joints were tested in the pull test. The obtained results showed the relation of the clinch joinability to the materials’ strain hardening exponent. The good quality and good strength joints, were obtained for materials with low value of strain hardening<span>  </span>exponent below n = 0,22.</span></p>

Quasi-static compression behavior and microstructure changes in low-cost AA6061 composites

2021 ◽  
pp. 095440622110553
Author(s):  
Hariharasakthisudhan P ◽  
Hariharasudhan T ◽  
Karthik S ◽  
Sathickbasha K ◽  
Surya Rajan B
Keyword(s):  
Aspect Ratio ◽  
Strain Hardening ◽  
Axial Strain ◽  
Low Cost ◽  
Research Work ◽  
Strain Hardening Exponent ◽  
Static Compression ◽  
Compression Behavior ◽  
Maximum Value ◽  
Quasi Static Compression

The workability study of the composites enhances the understanding of the degree of plastic deformation that can be employed on it. The current research work highlights the response of the low-cost aluminum composites reinforced with exhausted alkaline battery powders under quasi-static compression. The effect of reinforcements and aspect ratio against the strain hardening exponent and strength coefficients were investigated. The microstructural changes after quasi-static compression were studied and related to the changes in the property of the composites. The composite with 6 wt.% of reinforcement showed the least amount of porosity as 1.2%. In most of the cases, the maximum value of average strain hardening exponent with respect to axial strain was noted in the composites with 6 wt. % of reinforcement. The lowest aspect ratio of 0.5 showed the maximum workability in the composites. The average strength coefficient was found to be maximum (308.58 MPa) in the composite with 2 wt.% reinforcement. The elongated grains and slip bands were observed in the microstructure of the compressed specimens.

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