Causes and solutions for cracking of coextruded and weld overlay floor tubes in black liquor recovery boilers - Authors point to SCC as the likely mechanism

Cracking of coextruded recovery boiler floor tubes is a safety and an econo mic issue to mill operators. To determine the cause of cracking and identif y a solution, extensive studies, described in this and three accompanying p apers, are being conducted. This paper presents results of studies to chara cterize both the cracking and the chemical and thermal environment. Based o n the results described in this series of papers, a possible mechanism is p resented and means to lessen or totally avoid cracking of floor tubes are o ffered.