钢铝过渡接头的应用研究

摘要

Aluminum alloy is for the first time used as the superstructure material onboard ship to lower gravity center, reduce weight and increase speed. In the past, the aluminum alloy superstructure was connected to the steel hull by rivets. Now, this is replaced gradually by steel-aluminum transition joint with the advantages of welding technique, water-proof, corrosion-resistant and simplified construction process. However, quality deficiency was found in the form of steel-aluminum transition joint delaminating during construction, which directly influences ship’s quality. This paper elaborates the causes of steel-aluminum transition joint delamination with its characteristics and optimizes the welding joint shape of the transition joint, the connection form among the joint, and the connection between the steel hull and the aluminum alloy superstructure, where the thickness of welding spot is controlled not to exceed the steel-aluminum composite interface, the distance between the welding spot and the interface is controlled >3mm, the critical temperature of the composite interface is controlled to make the interface temperature lower than the critical temperature during welding, and redundancy for safety is considered. Thus the key technologies for joint delaminating are mastered via the optimization of the steel-aluminum transition joint connection and the welding techniques.%为降低船舶的质量重心、提高航速，某型船上层建筑首次采用铝合金材料。以往铝合金材质的上层建筑与钢质主船体采用铆钉连接，现已逐渐被钢铝过渡接头所替代，其优点为采用焊接工艺、水密性好、耐腐蚀，还使得建造工艺大为简化，但在实际建造中出现了钢铝过渡接头分层的质量问题，直接影响船舶质量。对此，阐述如何从钢铝过渡接头特性出发，对钢铝过渡接头分层的原因进行分析，对钢铝过渡接头之间的焊接接头连接形式以及钢铝过渡接头与钢质主船体、铝合金上层建筑的连接形式进行优化；控制钢铝过渡接头焊接时焊点的厚度，焊接时不超过钢铝复合界面，且焊接点与钢铝复合界面的距离>3 mm；控制复合界面临界温度，焊接过程中界面温度应低于临界温度，并留有安全裕度。通过优化钢铝过渡接头连接结构形式及焊接工艺规则，掌握了解决钢铝过渡接头分层原因的关键技术。