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POSCO Tests Corrosion Resistance of Steels with ZwickRoell Creep Testing Machines

POSCO, with an annual production of over 40 million tons, is one of the largest steel producers in the world. South Korea’s first integrated steel mill is headquartered in Pohang and produces steel products for the automotive, shipbuilding, energy and construction industries, as well as for machines and home appliances. The company’s objective is to secure its competitive position in the long term and support future trends with its premium steel.

Importance of corrosion resistance in the automotive Industry

POSCO is a supplier for well-known automobile manufacturers in Japan, the Americas, Korea and Europe, providing different types of steel for the chassis, drive and exhaust system, each of which has specific properties in terms of hardness, ductility, weldability, corrosion resistance, etc. The research and development center in Songdo is mainly dedicated to evaluating the corrosion resistance of automotive steels.

Requirement for extended creep tests in salt fog atmosphere

To meet customer quality requirements, POSCO steels for the automotive industry are tested for their long-term creep strength and corrosion resistance. In collaboration with ZwickRoell in Fürstenfeld, a testing solution was developed for salt spray tests with load stages based on ISO 9227. Because of the high demand for these special tests, POSCO chose to move forward with two of the new testing machines.

ZwickRoell tackles customer-specific test tasks

For this special test task, the proven electromechanical creep testing machine Kappa 100 DS was specially modified and equipped with a salt spray chamber at ZwickRoell in Fürstenfeld. The load frame was brought to a horizontal orientation and the width of the test area was increased to 1500 mm, in order to position the salt spray chamber in the center of the test area. A 5% salt fog atmosphere at a temperature of up to +50°C is created in the 600-liter volume salt spray chamber. To ensure undisturbed oxidation of the specimen, condensation is discharged in a controlled manner on the wall of the specially shaped protective cover, preventing disruptive drops on the specimen. Because of the corrosive salt fog, a load string made of seawater-resistant stainless steel, specimen adapters made of a nickel-base alloy and a suitable exhaust system are implemented.

Unique testing solution and satisfied customer through global collaboration

Since their successful installation and commissioning in the laboratory in Songdo, both testing machines have been in permanent use at POSCO. Other company divisions, customers and cooperating universities have shown interest not only in the test results, but also in the unique design of this testing solution. The flexibility, with which our sales partner in South Korea met the customer requirements, the technical know-how provided by the engineers from ZwickRoell in Fürstenfeld and the excellent collaboration of everyone from around the world involved in this project, resulted in not only a unique testing solution, but most importantly a more satisfied customer.