Due to their combination of excellent corrosion- and mechanical properties, duplex stainless steels are gaining more importance in chemical industry, oil- and gas exploration and for general applications. Most of the products used (pipes, profiles, flanges) are the result of different kinds of deformation processes. Apart from this, the need for initial components like valve bodies and pumps can be satisfied in a functional and economical superior way by cast components.

Pleissner Guss is a qualified supplier for cast armature- and pump components in duplex and super duplex stainless steel with an annual Production of 60 tons in 1996.

Cast components of the kind mentioned are often showing a wide variety of different wall thicknesses. Especially high pressure parts and large size valve bodies often show significant differences in wall thickness of the flanges to the rest of the body. To handle the severe effects of differing cooling rates as direct consequence of wall thickness on precipitation behaviour, susceptibility for hot cracking, general mechanical and corrosion properties is the task of the foundryman, who has to fulfil the expectation of the customer for good mechanical and corrosion properties without regard of metallurgical given facts.

The following paper shows some results of investigations on the effects of grain size on mechanical and corrosion properties of stainless 2205- and 25Cr-type duplex steel.