Optimum design of pipe bending based on high-frequency induction heating using dynamic reverse moment

Abstract

Pipe bending by high-frequency local induction heating is an advanced technique used to bend pipes having a small bending radius and a large diameter. Although pipe bending is a widely used engineering process, the optimum process parameters are decided on the basis of a trial and error method by highly experienced field engineers. Hence, it is necessary to develop an integrated methodology for the optimum design of the pipe bending process. During hot-pipe bending using induction heating, the thickness of the outer wall of the pipe decreases because of tensile stress, but the thickness is not allowed to decrease by more than 12.5%. The use of the DOE method and a dynamic reverse moment is proposed for maintaining the thickness reduction ratio to within 12.5%, when D/t is high. The results of the proposed approach are found to be in good agreement with those of FEA.

Microstructure and Mechanical Behavior of X90 Bend Using Local Induction Bending

“…Induction heating is an advanced process that is widely used to bend pipes with small bending radius and large diameter. It is efficient, low-cost and provide products with good material properties [5][6][7][8][9][10][11].…”

Hydroforming of locally heat treated tubes

“…Laser bending of sheets is another technique where a nearly dieless forming operation is made possible by a concentrated thermal power [12]. In-process local heating is often employed in free [13] or dieless forming operations, such as dieless incremental forming [14] or dieless tube bending [15]. The reason is that when there is large contact between the blank and the tools, conduction heat transfer occurs [16] and, therefore, the temperature of all tools must be carefully and locally controlled, otherwise the local effects disappear.…”

Experimental Generation of STKN540B Steel Circular Tube Manufacture with Press Bending and Auto-Welding Correction

“…Especially when the steel tube is manufactured with the steel plate of 600MPa or higher tensile strength and of 80~100mm ultra-thickness, it is critically necessary to secure the quality. But in the actual fields, the workers are depending on the conventional high frequency bending(Lee et al, 2011;Silva et al, 2012) or empirical way of trial and error so much that they can hardly realize the scientific manufacturing.…”