Uticaj zaostalih napona u zavarenom spoju na otkaz rotornih bagera

Abstract

Istraživanje uzroka pojave prslina u zavarenim spojevi-ma je pokazalo da zaostali naponi doprinose otkazu rotornih bagera SRs 1300.26/5 + VR ± 10 u eksploataciji. Izvedena su ispitivanja radi karakterizacije zavarenih spojeva (hemijski sastav, zatezne osobine, tvrdoća i udarna žilavost čelika, elektroda i zavarenih spojeva) i ocene sklonosti ka pojavi prslina. Na osnovu teorijske analize radnih i kritičnih napona napravljen je model zavarene konstrukcije rotora bagera i određena su kritična mesta za merenje deformacija mernim trakama. Utvrđeni su zaostali naponi usled zavarivanja i radni naponi za različite režime rada rotornog bagera i analiziran njihov uticaj na otkaze u eksploataciji. .

The investigation of welded joint cracking revealed that residual stresses contribute to the failure of bucket wheel excavator SRs 1300.26/5 + VR ± 10 in exploitation. Testing for welded joints characterization (chemical com-position, tensile properties, hardness and impact toughness of steel, electrodes and welded joints) and susceptibility to cracking assessment had been performed. Based on theoretical analysis of working and critical stresses, a model of bucket wheel excavator welded structure was developed and critical locations for strain gauge measurements were determined. Welding residual stresses were assessed as well as working stresses for different operating regimes of excavator and their effects on service failures. .