Effect of elastic-plastic behavior of coating layer on drawability and frictional characteristic of galvannealed steel sheets

2016 ◽  
Vol 30 (7) ◽  
pp. 3313-3319 ◽  
Author(s):  
Seongwon Lee ◽  
Mansoo Joun ◽  
Donghwan Kim ◽  
Jungmin Lee
2014 ◽  
Vol 794-796 ◽  
pp. 351-356
Author(s):  
Yohei Harada ◽  
Kozo Ishizuka ◽  
Shinji Kumai

High strength 2024 aluminum alloy studs were joined to galvanized, galvannealed and non-coated steel sheets by using an advanced stud welding method. Effect of the coating layer on the interfacial microstructure and the tensile fracture load of the joints were evaluated. A specially-designed stud having a circular projection at its bottom was pressed against a sheet surface. A discharge current was introduced from the upper part of the stud. Local heating could be achieved by a high current density at a contact point between the projection and sheet. The observation of joint area revealed the projection was severely deformed and spread along the sheet surface. The coating layer of the galvanized steel sheet was removed at the joint interface under the charging voltage of 200 V, while that of the galvannealed one locally remained on the steel surface even at 400 V. This would be strongly related to the melting or liquidus and solidus temperatures of each coating layer. Joining was not achieved at a low charging voltage in the non-coated and galvannealed steel sheets, while high tensile fracture load was obtained even at 200 V in the galvanized ones.


1991 ◽  
Vol 35 (B) ◽  
pp. 1211-1218
Author(s):  
Hiroharu Kato ◽  
Kiyotaka Imai ◽  
Hideya Tanabe

AbstractA new method, for the on-line determination of the composition and the coating weight of galvannealed (Zn-Fe-alloy-coated) steel sheets using monochromatic incident x-rays with two optical systems, is described. In the case of galvannealed steel sheets, it is difficult to determine the composition and the coating weight precisely by simple XRF, because fluorescent x-rays of Iron are emitted not only from the coating layer but also from the underlying steel sheets. We have developed an on-line analyzer with two optical systems which are different in incident angles, take-off angles and wavelengths of monochromatic incident x-rays. We determine the composition and the coating weight by solving simultaneous equations of the data which we derive using two optical systems. Using monochromatic x-rays enabled us to obtain high precision with high speed. We considered en-or factors in on-line measurement such as statistical error or fluctuation of the distance between the sensor head and steel sheets. This on-line analyzer has been applied to the continuous galvanizing line in our Fukuyama works successfully. As a result, we have been able to significantly improve product quality.


1983 ◽  
Author(s):  
H. ARMEN ◽  
A. LEVY ◽  
H. EIDINOFF

Author(s):  
A. Ajdari ◽  
P. K. Canavan ◽  
H. Nayeb-Hashemi ◽  
G. Warner

Three-dimensional structure of trabecular bone can be modeled by 2D or 3D Voronoi structure. The effect of missing cell walls on the mechanical properties of 2D honeycombs is a first step towards understanding the effect of local bone resorption due to osteoporosis. In patients with osteoporosis, bone mass is lost first by thinning and then by resorption of the trabeculae [1]. Furthermore, creep response is important to analyze in cellular solids when the temperature is high relative to the melting temperature. For trabecular bone, as body temperature (38 °C) is close to the denaturation temperature of collagen (52 °C), trabecular bone creeps [1]. Over the half of the osteoporotic vertebral fractures that occur in the elderly, are the result of the creep and fatigue loading associated with the activities of daily living [2]. The objective of this work is to understand the effect of missing walls and filled cells on elastic-plastic behavior of both regular hexagonal and non-periodic Voronoi structures using finite element analysis. The results show that the missing walls have a significant effect on overall elastic properties of the cellular structure. For both regular hexagonal and Voronoi materials, the yield strength of the structure decreased by more than 60% by introducing 10% missing walls. In contrast, the results indicate that filled cells have much less effect on the mechanical properties of both regular hexagonal and Voronoi materials.


2013 ◽  
Vol 22 (6) ◽  
pp. 1414-1427 ◽  
Author(s):  
Takahiro Namazu ◽  
Masayuki Fujii ◽  
Hiroki Fujii ◽  
Kei Masunishi ◽  
Yasushi Tomizawa ◽  
...  

Author(s):  
Yanping Yao ◽  
Ming-Wan Lu

The criteria of piping seismic design based on linear elastic analysis has been proved to be conservative, which is mainly because the influence of plastic deformation on piping dynamic response is neglected. In the present paper, a pipe under seismic excitation is simplified as an beam with tubular cross section subjected to steady axial force and fully reversed cyclic bending moment, and the elastic-plastic behavior of the pipe is studied. Various behavior of the pipe under different combinations of axial force and cyclic bending moment is discussed and the boundary curve equations between them are obtained. Also the load regime diagram for a pipe which is formed by the boundary curve equations in the loading plane is given, from which the elastic-plastic behavior of the pipe can be determined directly.


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