| Autor: |
Boriskin, Oleg I., Larin, Sergey N., Yamnikov, Aleksandr S., Nuzhdin, Georgiy A., Blagoveshchenskiy, Dmitriy I. |
| Předmět: |
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| Zdroj: |
Journal of Chemical Technology & Metallurgy; 2019, Vol. 54 Issue 6, p1305-1311, 7p |
| Abstrakt: |
This article analyzes the advantages of thin-walled steel cylindrical structures obtained by means of rolling and emphasizes the important role of technological heredity laws at all stages of their production. The authors estimate the state-of-the-art of thin-walled pipes production, analyze technical requirements for their quality and highlight the connection between the technological heredity and steel thin-walled pipes quality indicators. The initial ovality and curvature of steel billet axis, inherited from rolling or extrusion and fixing forces occurring under any technological influence cause billet deformation and a centering error before machining, assembling or controlling stages. Functioning of steel thin-walled cylindrical billets is substantially determined by the accuracy of their geometrical parameters, with wall thickness being the dominating one. The results of the statistical analysis of key geometrical parameters' accuracy have shown that the outer diameter of thin-walled steel pipes has the lowest accuracy. Determination of error type by means of harmonious analysis has given grounds to assume that they are caused by technological system deformations. The research of technological system rigidity has shown that the billet and the mandrel are the "weakest" points, while billet axis' and walls' deformations play the dominating role in causing the overall processing error. Therefore the authors have experimentally investigated the rigidity of machines and devices. It has been established that form errors in longitudinal and cross sections are formed as a result of a joint deflection of steel thin-walled billet axis together with the mandrel. The billet wall deflection during machining also plays a significant role. Rigidity research of mandrels of various types has shown that billet form errors in the longitudinal direction are connected with the couplings in mandrels' structures. Another feature of mandrels' influence on the accuracy of processing is such a specific error as a non-uniformly focused ellipse in the cross-section. This phenomenon is explained by changing rigidity of the mandrel in various radial directions. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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