scholarly journals INFLUENCE OF PLASTIC STRAIN HISTORY ON MECHANICAL PROPERTIES OF STRUCTURAL METALS : Part 4. Discussion concerning Strain Aging, Bauschinger Effect and Yield Locus

1978 ◽  
Vol 272 (0) ◽  
pp. 31-40
Author(s):  
MORIHISA FUJIMOTO ◽  
HIROFUMI AOKI ◽  
FUJIO ASAOKA
Author(s):  
Alan Dobson

The effect of repeated plastic strain on the mechanical properties of reeled super duplex tube used in the construction of umbilical riser systems is assessed. The impact of typical plastic strain cycles on the fatigue properties of tubing, mechanical properties of the tubing and the susceptibility of hydrogen embrittlement of the tubing has been investigated. There is evidence that plastic strain cycles have an effect upon the fatigue life of the tube; which can be attributed to a low cycle fatigue mechanism. There is no evidence that plastic strain cycling to specified limits has an effect upon the susceptibility of the material to Hydrogen Induced Stress Cracking (HISC) and typical plastic strain cycles have no degenerative effect upon the mechanical properties of super duplex tube and radial welds.


2016 ◽  
Vol 849 ◽  
pp. 376-381
Author(s):  
Ming Long Li ◽  
Yu Jie Geng ◽  
Chen Chen ◽  
Shu Jie Pang ◽  
Tao Zhang

The effects of cold-rolling with different reduction ratios of 70%-90% on the microstructure and mechanical properties of Ti50Zr30Nb10Ta10 alloy were investigated. It was found that the β-Ti phase in this alloy was stable under cold-rolling. With the increase in reduction ratio from 70% to 90%, the microstructure of the alloys evolved from deformed dendrite structure to fiber-like structure. The alloy cold-rolled with the reduction ratio of 70% exhibited optimum mechanical properties of combined high fracture strength of 1012 MPa and plastic strain of 10.1%, which are closely correlated with the dendrite structure of the alloy. It is indicated that the proper cold-rolling is an effective way to improve the mechanical properties of the titanium alloy.


2021 ◽  
Author(s):  
Sanjida Begum

Lightweight magnesium alloys are being increasingly used in automotive and other transportation industries to achieve energy efficiency. The objective of this thesis was to study the mechanical properties of two wrought alloys AZ31 and AM30. With increasing strain rate the yield strength and ultimate tensile strength increased and the strain hardening exponent decreased for AM30 and increased for AZ31. Both alloys exhibited stable cyclic characteristics at lower strain amplitudes and cyclic hardening characteristics at higher strain amplitudes. The Bauschinger effect was pronounced at higher strain amplitudes, resulting in asymmetric hysteresis loops in both alloys. The influence of strain ratio (Rs), strain rate, and initial straining direction on the cyclic deformation characteristics and fatigue life was evaluated. At low Rs, both alloys exhibited strong cyclic hardening, which decreased as Rs increased. Fatigue crack initiation was observed to occur from the specimen surface and crack propagation was basically characterized by striation-like features.


1984 ◽  
Vol 26 (7) ◽  
pp. 537-540 ◽  
Author(s):  
V. D. Kal'ner ◽  
B. I. Beilin ◽  
Ya. V. Shubert

1998 ◽  
Vol 552 ◽  
Author(s):  
B. Matterstock ◽  
G. Saada ◽  
J. Bonneville ◽  
J. L Martin

ABSTRACTThe characterisation of dislocation mechanisms in connection with macroscopic mechanical properties are usually performed through transient tests, such as strain-rate jumps, load relaxations or creep experiments. The present paper includes a careful and complete theoretical analysis of the relaxation and the creep kinetics. We experimentally show that the plastic strain-rate is continuous at the transition between constant strain-rate conditions and both load relaxation and creep test. The product of the plastic strain-rate at the onset of the transient test () with the characteristic time (tk) of the transient is found to be independent of , as theoretically expected. This is a clear indication that the assumptions underlying the theoretical analysis are relevant.


2021 ◽  
Vol 1035 ◽  
pp. 278-285
Author(s):  
Lei Chen Jia ◽  
Jian Min Yu ◽  
Guo Qin Wu ◽  
Wen Long Xu ◽  
Yong Gang Tian ◽  
...  

The compression behavior and mechanical properties of the Mg-13Gd-4Y-2Zn-0.5Zr (wt.%) alloy filled with intragranular long-period stacking ordered (LPSO) phases at different temperatures were investigated. The results showed that the higher the compression temperature, the smaller the plastic strain that the grains withstand. The grains changed from equiaxed to flat strips when compressed at 350°C, and the morphology of the grains did not change at 450°C. Due to the existence of DRX grains, compression at 450 °C didn’t cause large-angle kink, but the kink angle at 350°C was very large. DRX grains only appeared at the grain boundaries and around the intergranular LPSO phase at the beginning of compression, and only appear at the kink bands (KBs) after the lamellar LPSO phases begin to kink. DRX grains gradually increased with the KBs increasing.


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