Source: ASK Chemicals
Tailor-made products for ensuring the purity requirements for the melts for these special applications are just as much a focal point as special wire treatments, inoculants and inoculation methods.
The ferritic material EN-GJS-400-18U-LT was used for these cast components in particular because of its high ductility, i.e. the ability to reduce overloading by means of plastic deformation and to compensate sudden loads without rupture. The material also proves exceptionally successful when used at low or strongly fluctuating temperatures due to the ensured notched bar impact value of 12 joules at −20°C. The breaking strain is 18%. The required cast quality is achieved by applying the simultaneous engineering methods that begin with a simulation of the mold filling, followed by a simulation of the solidification and a simulation of the structural formation.
The wind turbine designs whose performance ranges up to 5 MW require cast parts made of cast iron with nodular graphite (EN-GJS-400-18U-LT) and a weight of up to 50 metric tons. They entail new dimensions in terms of sizes, mold material requirements, metallurgy, especially magnesium treatment and inoculation technique, and moving masses. Foundry suppliers who work in the wind power industry are thus challenged to face up to these developmental trends and to adapt accordingly with expertise, verified material properties of their products, equipment, and their capacities.
The cooperation between the supplier and the foundry specialist on site is accompanied by extraordinary synergy effects. A quick exchange of information is conducive to the foundry- and production-related optimization and the necessary further development of the ASK Chemicals products. Numeric simulation techniques for mold filling and solidification help to solve problems that would be very difficult to handle in terms of feeding, for example. Tests are conducted to gain insight into how the functionality of the components can be further optimized by means of casting-related changes. Weak points in the design or oversizing are thus identified at an early stage without the cast part having to be manufactured. ASK Chemicals’ expertise regarding their products is complemented in an optimum way by the caster’s comprehensive knowledge of mold material, material and metallurgy.
Source: ASK Chemicals