On properties of titanium weldrawn tube

Abstract

Titanium tubing has increased its importance in chemical industries because of its excellent corrosion resistance.At the present time, titanium tubes are manufactured primarily by the following two processes in the authors' company.1 Hot extruding, which is usually followed by cold drawing.2 Rolling sheet strip into tube form, and shielded are welding with or without suhsequent cold drawing.The titanium tube manufactured by means of welding and cold drawing, is called “weldrawn tube” representing high quality.The authors prepared the KS-50 titanium (Commercially high purity grade) weldrawn tubes, for the welding of which an inert gas chamber welding apparatus wat used.This report involves the investigations of these weldrawn tube on their mechanical properties and microstructure of cross section.The results are summarized as follows:1 Dimensional test of titanium weldrawn tube indicated that wall-thickness and concentricity could be maintained within very narrow limits. Surface appearance was also excellent.Microstructure as well as hardness of the tube cross section became uniform in welded and unwelded zones by cold drawing and annealing.2 In practical tests, titanium weldrawn tube showed that its values exceeded those of JIS specification on seamless and electric welded steel pipes.3 The weldrawn tube of 23OD×1.65t withstood hydraulic pressure of 600kg/cm2 G and the permanent strain of the tube at the test was 5×10-3 in circumference.4 Titanium clad steel pipe was manufactured by the authors as one of applications of titanium weldrawn tube.