Establishing criteria for root and toe cracking of load carrying cruciform joints of pressure vessel grade steel

摘要

In this investigation an attempt has been made to establish a criterion to forecast the possible crack initiation region (toe or root) in double fillet welded load carrying cruciform joints and also to know the probable failure mode. Cruciform joints were fabricated from pressure vessel grade (ASTM 517 'F' grade) steel using shielded metal arc welding (SMAW) and flux cored arc welding (FCAW) processes. Fatigue crack growth experiments were carried out in a mechanical resonance vertical pulsator (SCHENCK 200 kN capacity) with a frequency of 30 Hz under constant amplitude loading (R = 0). It was found that the fatigue crack initiation lives (root crack or toe crack) were relatively lower in the joints fabricated by FCAW process than the joints fabricated by SMAW process.