Charpy toughness and microstructure of vibrated weld metalBogdan Pučko
, Vladimir Gliha
, 2006, izvirni znanstveni članek
Opis: Vibration during welding can be used to obtain certain changes in mechanical properties of weld metal. Research work on the influence of vibration on the secondary microstructure of welds and hence on the Charpy toughness was performed. Vibration during welding exhibits positive effects on the microstructure constituent formation. Multipass welding was simulated with reheating of the original single pass weld in order to obtain similar microstructure to multipass welds. Microstructures were examined with an optical microscope. Additionally, fractographic examination of the rupture of Charpy specimens was performed. Changes in the microstructure according to vibration were observed which affect toughness of the weld metal. Vibration during welding was rated more effective in the case of reheating the weld metal, which is the case in multipass welding.
Ključne besede: welding, welded joints, mechanical properties of metals, ferrite, vibration, microstructure, toughness, notched bar testing, weld metal
Objavljeno: 31.05.2012; Ogledov: 1438; Prenosov: 68
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Fuzzy logic based quality monitoring in short-circuit gas metal arc weldingMarjan Golob
, Arpad Köveš
, 2007, izvirni znanstveni članek
Opis: Conventional methods, e.g. destructive and non-destructive testing methods, are expensive and time-consuming; therefore, possibilities of online and automated quality control of a welding process during welding as such are investigated. The paper deals with the possibilities of application of fuzzy logic to the analysis of weld quality, particularly assessment of the weld surface condition by means of measurable electric signals emitted during welding. A simple fuzzy inference system was realised which could relatively efficiently assess the weld quality on the basis of time variations of the welding voltage and short-circuit time in a certain time window.
Ključne besede: fuzzy systems, fuzzy logic, gas metal arc welding, GMAW, quality monitoring, statistical analysis, quality control, weld quality
Objavljeno: 31.05.2012; Ogledov: 1024; Prenosov: 71
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Vloga in nastanek mikrostrukturnih sestavin M-A v zvarnih spojih maloogljičnih visokotrdnostnih konstrukcijskih jekelZdravko Praunseis
, Masao Toyoda
, Alojz Križman
, Mitsuru Ohata
, 2001, pregledni znanstveni članek
Opis: The existence of martensite-austenite constituents in the weld metal and heat-affected zone seriously reduces the fracture toughness of the welded joint. Therefore, we have investigated the formation of the martensite-austenite constituents when high-strength low-alloy steel is welded with a high heat input or using multi-pass welding. This paper deals with the effects of martensite-austenite constituents on the fracture toughness, the metallurgical features of the martensite-austenite constituents, and the prevention and elimination of the martensite-austenite constituents in the welded joints.
Ključne besede: arc welding, high-strength low-alloy steels, microstructure, martensite-austenite constituents, weld metal, heat-affected zone, cooling rate
Objavljeno: 01.06.2012; Ogledov: 1122; Prenosov: 59
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