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The pore and crack formations in the weld bead during underwater wet welding are the main cause of failure to reach the required mechanical properties of the weld metal. These defects are closely associated with the decomposition of the water molecule under electric arc conditions. In this paper, the thermodynamic calculations of the complex process of the water decomposition under the conditions of high electric arc temperatures at a pressure of 1 atm of steam are discussed. The values of the partial pressures of the five main products of the vaporizations and decomposition of the water (H2O(g), H2, O2, H and O) are calculated for temperatures between 1870 and 4000 K. Due to the fact that atomic hydrogen is mainly responsible for pore formation in the weld metal, its partial pressure as a function of partial pressures of atomic oxygen and steam (water vapour) is expressed. Hydrogen solubility values in the liquid metal under the conditions of underwater wet welding at depths of 50 and 100 m, and a comparison between the thermodynamic calculation and porosity measurement results at depths of 50 and 100 m, are presented. [ABSTRACT FROM AUTHOR]

The submerged arc welding (SAW) process is widely used in Cuban industries and it is highly reliable. The flux and wire electrode feeds are carried out simultaneously during the SAW process. The flux forms a layer, and beneath it is the wire producing the electric arc. During the deposition of the flux, a certain amount of air (1.293 g/l and filling 48% of the total layer) stays hidden among interstices between the grains. The air is formed of approximately 21% oxygen and 77% nitrogen; these gases are undesirable during the SAW process. When the granulometric distribution and the grain shape of the flux are not known, an unexpected effect can occur on the mechanical properties of the weld bead. This effect has sometimes been imputed to other problems such as incorrect previous calcinations of the flux. The conjunction of the morphological characteristics of the grain and its granulometric distribution are aspects that have not been sufficiently studied, in relation to the air potentially occluded in the free spaces between the grains. [ABSTRACT FROM AUTHOR]

The relationships between the compositions of a submerged arc welding bonded flux with the structure and properties are evaluated. Evaluations about the particularities of the flux structure are made based on the relationships O:Si and O:(Si + Al). Analysing the obtained welds with the different fluxes, the regression equations that correlate the contents of the elements in the welds and the flux oxide system for a specific condition of welding regime are established. The behaviour of the fundamental elements of the weld is analysed as a function of the flux basicity, the activities of MnO and SiO2 and the MnO/SiO2 relationship within the eutectic range of the binary system. [ABSTRACT FROM AUTHOR]

The article points out some health risks caused during the welding process, a well extended work in the sugar industry. It makes emphasis on health damages caused by the resulting smoke of this process, and it provides some of the necessary measures for avoiding or diminishing these hazardous effects. [ABSTRACT FROM AUTHOR]

This paper shows a valuation of different methodologies used to calculate the Transfer Coefficients (Kt) of alloy elements during the metallurgist process of Submerged Arc Welding taking in account the contribution of alloy elements starting from flux and from the wire-electrode. It is experimentally determined the chromium and manganese Kt in ceramic and commercial HF-600 flux. [ABSTRACT FROM AUTHOR]

The present work approaches the obtaining of manganese flux to be used in Submerged Arc Welding (SAW). This study starts with a transformation of a manganese mineral by the increase of temperature and the addition of other minerals. These conditions modify the binary system MnO-SiO2 and the behavior of the flux. A comparative analysis of the technological behavior of the flux during the welding process as well as the chemical and mechanical properties of the junctures in relation with trademark fluxes are presented. [ABSTRACT FROM AUTHOR]

The internal combustion motors are the main energy and source of the harvesting and transportation that intervene in the crop of sugar cane. This work exposes the evaluation of the properties obtained in the layers of the recovered-by means of recharges with the process SAW-stumps of crankshafts of different motors of internal combustion, with the use of an alloyed agglomerate flue developed in the Welding Research Center (CIS) of the Central University "Marta Abreu" de Las Villas. This flue is dedicated to recharging the surfaces that work subjected to the friction waste, basically crankshafts and other axis-like parts. A forecast is also done of the working capacity of different alternatives by means of wear tests. The results are valid for a great range of crankshafts built of different materials, of motors already well known or new ones recently introduced in the country. [ABSTRACT FROM AUTHOR]