Study on Underwater Explosive Welding of Al-Steel Coaxial Pipes

Abstract

Abstract:In order to solve the aluminum surface ablation issue of Al-Steel bimetallic pipes manufactured by the explosive welding technique, a novel explosive welding system has been designed to weld Al-Steel coaxial pipes. The stand-off distance was chosen according to an empirical formula. A special Explosive Cord with an aluminum coating was used as the explosive. Four experiments were performed using Explosive Cords 1, 2, 3 and 4, respectively. In each experiment, three reliable PVDF (Polyvinylidene Fluoride) piezoelectric film sensors were used to sample the impact pressure between the parent pipe and the flyer pipe along the detonation direction. p-t Curves were obtained at different points on the bimetallic pipe manufactured by Explosive Cord 1. In order to observe the inner surface and to judge the bonding interface, specimens were cut along the axial direction. BSE (Backscattering Electron) images of the interfaces were obtained. According to these pictures from all of the specimens cut along the axial direction, the surface ablation phenomenon has disappeared. The bimetallic pipe manufactured by the new welding system using Explosive Cord 3 has an irregular wavy interface, between micro and small wavy interface, which is one of the best bonding forms.

Mechanical analysis of 20/316L bimetal composite pipe formed by spinning

“…The forming technology of metal composite pipe mainly includes hydroforming, drawing forming, explosion forming and spin forming [7][8][9][10]. Many scholars and https://doi.org/10.1007/s42452-021-04932-7…”

Experimental study of Cu/Fe underwater self-constrained explosive welding tube

“…The explosive welding process also needs to properly control the thickness of all tubes and the distance between each part. When the coaxial tube is explosively welded, the ideal gap distance S ≈ (0.5–1.0) × δ , where δ represents the thickness of the inner tube [24]. The wall thickness of the copper tube used in the experiment was 2 mm, and the ideal gap was 1–2 mm, and the gap was taken as 2.5 mm in order to approach the ideal gap while using industry standard size tubes as raw material.…”

Optimization of spinning parameters of 20/316L bimetal composite tube based on orthogonal test

“…B. Cao and Z.S.Zhang introduced ANSYS finite element software to analyze the composite dynamic process, and obtained the displacement of key nodes of the liner and the stress distribution of the composite tube after forming [17]. Yu yong et alapplied PVDF piezoelectric thin film sensor to measure the dynamic parameters of the explosive welding and studied the impact pressure of the aluminum layer on the steel layer in the aluminum-steel underwater explosive [18]. The explosive forming of metal composite tubes also has been reported in other literatures [19][20][21].…”