Development of Flexible High Production Technique for High Quality and Excellent Formability ERW Tube by CBR Forming Mill

There has been developed a new technology to fabricate low-cost stainless electric-weld tubes, which have an improved quality with an expanded allowable range of tube size for rolls and exhibit severe working resistance even without pipe heat treatment. The stand structure and characteristics of the chance-free bulge roll forming mill are presented. The non-annealed electric-welded stainless steel pipe for automotive exhaust by CBR mill is compared with that by conventional process in elongation and bend working performance. It is demonstrated that use of CBR mills results in a 16.5% increase in qualified product rates, 14% in utilization of capacity, and more than three times in productivity.