Papers by Keyword: Stainless Steel Pipe

Abstract: Dissimilar metal welding is widely applied to meet the rquirement of transition in mechanical properties and/or difference in working conditions. For instance, even though AISI 304 and AISI 316L are both belong to austenitic stainless steels, but they are applied in different working environment. AISI 304 is used at high temperature applications, whereas AISI 316L is used at low temperature. Repair welding is able to return a part back to its normal service life if weld failure happened due to service deterioration or defects during fabrication stage. However, repetitive heat input due to repair welding will cause changes in welded structure and properties. In this article, the effect of repetitive repair welding of dissimilar austenitic stainless steel pipes to the microhardness, tensile strength, microstructure and quality of the weldment has been reviewed.

Abstract: A simple processing method for splitting pipes in the axial direction using a cutting tool was investigated. The special tool developed in this study was pressed into the pipes in the axial direction, and the pipes were split very smoothly without any lubricant. This cutting method did not form fine chips, did not produce a significant heat effect on the inner wall surface. The splitting experiment was carried out with pipes constructed of aluminum and stainless steel. The outer diameters of the pipes were approximately 50 mm, and the thicknesses of the wall varied from 1 to 3 mm. The aluminum pipes were split very smooth by the tool, and curled strip-shaped chips were created by the splitting. On the other hand, the stainless pipes were greatly deformed, making them difficult to cut. Therefore, it was necessary to prevent deformation of the pipe by attaching an outer tool. The outer tool made it possible to cut stainless steel pipes.

Abstract: The growing demand for lightweight products has been increased by the rapid development of automobiles in order to reduce fuel consumption. One of the keys to reduced fuel consumption is to utilize high-strength, light materials like stainless steel that are difficult to form due to their high strength. This paper discusses the development of pressing technology that forms relatively high-strength stainless-steel pipe with surface screw threads. Our new press-forming process was tested to obtain accurate screw threads on stainless-steel pipe. A 3-D digitizer was used to measure the accuracy of pipes manufactured by the proposed pressing method. Our proposed press-forming method decreases pipe thickness more effectively than conventional roll-forming technology. The maximum decrease in material thickness produced by conventional roll forming was 40%. The maximum decrease in material thickness produced by our press-forming process was 20%.