Development of bus body technologies in terms of corrosion and durability

Abstract

The object of this study is the technology of bus bodies and the formation of recommendations for design bodywork subject to the regulated durability of the body introduced into production. Advancing the technology of manufacturing bus bodies implies improving anti-corrosion protection, using new polymeric materials, and reducing the length of welds. The issue of corrosion resistance of bus bodies has been considered. It is established that the use of new polymeric materials will increase the corrosion resistance of bus bodies while existing technologies weakly protect against corrosion (resource up to 5 years). The peculiarity of this study is that the adhesion of new materials has been tested, with artificial aging, which confirms the durability of glued joints. According to the old technology, the body was exposed to anticorrosive treatment after welding the cladding with uncovered places left between the frame and body cladding, which provoked corrosion. The main idea is that in the new technology, the cladding is welded or glued after the body frame is fully coated with primer. New technologies and materials not used in the automotive industry have been proposed. Three variants of technologies were put into production. First: the welding of steel zinc sheets. In welding sites, the frame is covered with conductive primer. It was implemented for school buses (after 7 years, without damage). Second: gluing steel zinc sheets. It was implemented for city buses (after 6 years, without damage). Third: gluing sheets from composite materials not used in the automotive industry. The transition to new adhesive cladding technologies from composite corrosion-resistant materials instead of steel sheet, reduces by 2.5–3 times the length of welds (up to 20 years without damage). The studies have confirmed the strength of glued joints (cohesion rupture exceeds 95 %). The reliability of glued joints and high corrosion resistance of the body have been confirmed in the operation of buses. The scope of practical use of the results: bus-building plants. The reported results are suitable for production of all types while cataphoretic coatings are only for mass production