Application and Upgrading of On-line Monitoring System for Measurement and Processing of Electric Signals at Arc Stud Welding Process
As the application of on-line monitoring system is shown to be a good solution during monitoring of main welding parameters at different welding processes, this paper describes application and upgrade of on-line monitoring system developed at Mechanical Engineering Faculty in Slavonski Brod. Experimental part of the paper shows application of on-line monitoring system during welding of two types of studs with application of activating flux for ATIG process (VS-2E) on the base metal surface. Monitoring of main welding parameters (welding current and voltage) was conducted during welding of studs usually used in steam boiler production (stud diameter: 10 mm), and welding voltage was monitored on the studs (shear stud) of 22 mm diameters used in bridge construction. The goal of monitoring and analyse of main welding parameters is to evaluate the connection of electric arc parameters variations with the presence of activating flux.
The Current State of the Art and the Issues of the Drawn Arc Welding of Studs Performed Using a Ceramic Ferrule
The authors performed the state-of-art analysis of recent achievements concerned with drawn arc stud welding involving the use of ceramic ferrules. The research focused on surface preparation, technological parameters, process limits and magnetic arc blow. Because of the complexity and correlations of primary electromagnetic phenomena in stud welding processes as well as due to the lack of simple and practically applicable theoretical explanation of their effect on welding results, emphasis was given to demand for industrially applicable simulation tools enabling the forecasting of stud welding results. It is believed that the above-named goal could be achieved using the non-linear regression model of an artificial neural network based on empirical data obtained on a real-time basis from simple process controlling measurement circuits.
The crystal structure of stilpnomelane. Part II. The full cell
Summary The structural formula of stilpnomelane averaged from 37 representative literature analyses and based on the determined structure is (Ca,Na,K)4(Ti0·1Al2·3Fe35·5Mn0·8Mg9·3)[Si63Al9](O,OH)216·nH2O. Ferrostilpnomelanes have up to 12 R 3+ cations in the octahedral sheet, ferristilpnomelanes commonly have between 24 and 30 R 3+ cations, rarely up to 37. The two groups can be distinguished by accurate X-ray powder diffraction, ferrostilpnomelanes having d 001 less and a greater than have ferristilpnomelanes. The unit cell is triclinic, a = b∼21·8 Å, γ = 120°, d 001∼12·2 Å, P . Hexagonal groups or ‘islands’ of 24 silicon-oxygen tetrahedra co-ordinate to the octahedral sheet, the centres of the ‘islands’ are displaced by 5a/12, 8b/12 on either side of the octahedral sheet as a result of warping of this sheet to permit articulation with the smaller tetrahedral sheet. The 24-tetrahedra ‘islands’ are linked laterally by 6-member rings of inverted tetrahedra, which in turn link at their apices to like rings connecting the next sheet of ‘islands’. Thus a single tetrahedral layer is 4 tetrahedra thick and has symmetry 6/m. The 6-member rings of tetrahedra act as hinges permitting up to 0·5 Å extension or contraction of the tetrahedral sheet to accommodate variations in the octahedral sheet dimensions with varying R 2+/R 3+ ratio.