Influence of Rare Earth Metals on Mechanical Properties of Pipeline Steel

Abstract

Rare earth metals (RE) additions to pipeline steel were improved necessary mechanical properties, comparing with CaSi addition treatment . The yield, ultimate tensile strenghths were raised with optimal RE addition amount was obtained to 0.05kg/t and ratio RE/S to 0.217. The percentage of elongation was increased with optimal RE addition amount was obtained to 0.07kg/t and ratio to 0.212. The comparision with pipeline steel of GOST 20, RE additions were affected on sulphide shape control, macrostructure and microstructure of steel ingots impr-oving in yield, ultimate tensile and percentage elonga-tion after rolling. The results have been varified in full scale plant trials.