Wuppermann supplies a wide range of products for a host of applications in the construction industry, including galvanized steel strip, galvanized tubes for extra protection against corrosion, and a variety of tube and sheet-metal components.
Galvanized steel strip and galvanized tubes for high corrosion prevention
Conventionally galvanized steel tubes, which have been batch-dipped in an immersion bath, are unable to meet the highest quality requirements. This process not only involves substantial logistical effort but also results in a product that is formable only to a limited degree. Moreover, the protective zinc coating is fragile. This is because the process leads to substantial formation of an intermetallic phase at the interface between the two elements zinc and steel (fig. 1). This phase is brittle, cracks during reshaping, and can flake over large areas if subject to mechanical stress. As a result, the corrosion protection is lost, and red rust forms very rapidly as the steel comes into contact with atmospheric oxygen.
In the continuous hot-dip galvanizing process used by Wuppermann, the zinc coating applied to the steel strip consists of only a pure zinc phase (fig. 2), even in the case of very high zinc deposits (Z1200). The characteristic formability of zinc is therefore preserved. As a result, the hot-dip galvanized strip from Wuppermann can be formed at will without any danger to its protective coating.
Wuppermann also supplies steel tubes with an especially high resistance to corrosion for particularly demanding requirements in areas such as the construction industry. For this purpose, Wuppermann has developed an all-round galvanizing process that is unique in terms of both technology and economic efficiency. The tube formed from galvanized strip is welded and then immediately galvanized in a continuous process, both on the outside and the inside of the weld. There is no formation of an intermetallic phase (fig. 3). As a result, the entire zinc coating of the tube retains its formability, even in the weld area, and therefore its full resistance to corrosion.
Fig 1. Steel tube treated by batch galvanization
Fig 2. Steel tube treated by continuous galvanization Fig 3. Steel tube with fully galvanized inner weld