The forming technique and quality characteristics of ERW rifled boiler tube.

Abstract

Rifled boiler tube has high heat-transfer efficiency, and therefore is used for the furnace wall tube in the large power plant boilers.The manufacturing technique which can ensure high dimensional accuracy of rifled tube were developed through experiments to clarify the rifle forming mechanism and develop the dimensional control method in manufacturing process. As a result, mass production of rifled tubes of good dimensional accuracy has now been made possible by cold drawing process.Furthermore, it was made clear that the use of the ERW (Electric Resistance Welded) tube whose dimensional accuracy is excellent is advantageous because the dimensional accuracy of the rifled tube is influenced by that of the base tube (the tube before drawing).The quality characteristics of ER W rifled boiler tube was also studied to find that the high temperature strength including creep rupture strength of the rifled tube under internal pressure depends on the dimensional accuracy of the wall thichness of the rifled tube at the groove.