Method of making high strength steel tube

摘要

Improved steel profiles having superior material characteristics are obtained by rolling a precipitation-hardenable fine-grain steel, cooling it from a final rolling temperature above the A1-temperature down to a temperature of about 400 DEG C. in an atmosphere in which it is allowed to overage, whereupon the steel plate or strip is then cooled down to room temperature and cold-processed to form an open profile [which can thereupon be converted into a tube by welding together its longitudinally extending edges and] which is then subjected to solution-annealing in order to dissolve coarse precipitants and subsequently further cooled to form finely dispersed precipitants in the profile.