Mechanical working and steel processing IV

Author(s):  
S. Bharati ◽  
B. Patil ◽  
H. Vishwanath ◽  
P. Hittalamani ◽  
S. Joshi

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 38
Author(s):  
Matthias Weiss ◽  
Peng Zhang ◽  
Michael P. Pereira ◽  
Bernard F. Rolfe ◽  
Daniel E. Wilkosz ◽  
...  

This study investigates the effect of grain size and composition on the material properties and forming limits of commercially supplied stainless steel foil for bipolar plate manufacture via tensile, stretch forming and micro-stamping trials. It is shown that in commercially supplied stainless steel the grain size can vary significantly and that ‘size effects’ can be influenced by prior steel processing and composition effects. While the forming limits in micro-stamping appear to be directly linked to the plane strain forming limits of the individual stainless steel alloys, there was a clear effect of the tensile anisotropy. In contrast to previous studies, forming severity and the likelihood of material failure did not increase with a decreasing channel profile radius. This was related to inaccuracies of the forming tool profile shape.


1971 ◽  
Vol 10 (1) ◽  
pp. 21-27 ◽  
Author(s):  
M. A. M. A. Younes ◽  
P. S. Walker ◽  
P. C. Seller ◽  
D. Dowson ◽  
V. Wright

2017 ◽  
Vol 62 (3) ◽  
pp. 1443-1447 ◽  
Author(s):  
T. Maciąg ◽  
J. Wieczorek ◽  
B. Węcki

AbstractElectropolishing is electrochemical method used in metal working that has a vital role in production of medical apparatus, in food or electric industry. The purpose of this paper is to determine optimal current parameters and time required for conducting electropolishing process from the perspective of changes of surface microgeometry. Furthermore, effect of different types of mechanical working used before electropolishing on final surface state was evaluated by observation in changes of topography. Research was conducted on electrolytic copper and brass. Analysis of surface geometry and its parameters (Ra, Sa) was used as criterion describing efficiency of chemical electropolishing. Results of the experiment allow for current parameter optimization of electrochemical polishing process for selected non-ferrous alloys with preliminary mechanical preparation of the surface.


Author(s):  
I. Yu. Pyshmintsev ◽  
D. A. Pumpyanskyi ◽  
Yu. O. Kamenskih ◽  
I. N. Poznyakovsky ◽  
I. L. Permyakov

Strengthening mechanisms applied for modern line pipe steel design were studied. Low carbon steels alloyed with Mn, Mo, V, Nb processed by the way of controlled rolling were developed for spiral welded X65-X80 line pipes up to 1420 mm diameter. Formation of the microstructure during steel processing was studied. The effects of typical microstructure for the steels on mechanical properties, strain hardening behavior and Bauschinger effect were studied. Main metallurgical factors affecting on strength measured in plates and pipes were revealed using physical and computer simulations.


2021 ◽  
Vol 53 (6) ◽  
pp. 139-174
Author(s):  
Laetitia Lenel

The article investigates the methods and conceptions of statistical inference used in business forecasting in the United States and in Europe in the 1920s. After presenting the methods and arguments used by the members of the Harvard Committee on Economic Research in the first years after its establishment in 1919, the article explores the far-reaching changes in method and conviction from 1922 on. The members’ realization that the future evolved differently than predicted prompted them to give up their hope for mechanical means of forecasting and to revoke their calls for the employment of the mathematical theory of probability in economics. Instead, they established an extensive correspondence with economic and political decision-makers that allowed them to base their forecasts on “inside information.” Subsequently, the article traces European attempts to adopt the Harvard Index of General Business Conditions in the early 1920s. Impressed by the seemingly mechanical working of the Harvard index, European economists and statisticians sought to establish similar indices for their countries. However, numerous revisions of the Harvard index in the mid-1920s cast doubt on the universality of the index and the existence of stable patterns and led European researchers to pursue different paths of investigation. The article complicates the larger history of statistical inference in economics in two meaningful ways. First, it argues that statistical inference with probability was not the long-sought solution for the problem of objectivity but a long-contested, and repeatedly discarded, approach. Second, it shows that these contestations were often triggered by deviations between forecasts and the conditions actually observed and by this means argues for the importance of the historical context in the history of economics.


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