The forces in joining the copper pipe to the aluminum radiator through interference fit are analyzed and calculated,and a new technique of pipe screwing and expanding is introduced so that the force of moving forward when the pipe is being expanded is reduced.

This paper compares the pipe-expansion screw with old-type mild steel expansion bolt in the their functions and application scope, and introduces the properties and application prospect of the new proprietary product.

This article analyzes occurrence mechanism and reason of forming weld protruding of spiral submerged arc welded pipe and influence of peaking to protruding of steel pipe,and also put forward effective control method such as draw up the best process parameter,make steel plate edge shape norm,prebending steel plate edge to settle protruding problem.

In accordance with specialty of double wires welding process of inside welding for spiral submerged arc welded pipe,a set of internal welding double wires welding unit is developed.

Mathematical analysis for the diameter tolerance of spiral welded pipe;

Improvement upon the lubrication of forming rollers for spiral welded pipe;

In way of weld field,the article introduces application foreseeing of this technology,also discusses this technology application into 4 aspects:forming roller design and manufacturing,design of longitudinal welded pipe mill,the control of deform process and forming stress in longitudinal welded pipe in production,and the control of pipe residual stress in spiral welded pipe in production.