Relationship of recovery boiler parameters and primary air port cracking

Cracking of 304L stainless steel/carbon steel co-extruded tubes that form primary air ports in most recovery boilers is being observed with increasing frequency in North American boilers. In-situ measurements using thermocouples mounted on the air port tubes have shown that the tubes that experience the most severe temperature fluctuations are the ones most likely to experience cracking. Studies have been conducted to relate these temperature …