Spray water cooling is an important technology used for the cooling of materials from temperatures up to 1800K. The heat transfer coefficient (HTC) in the so-called steady film boiling regime is known to be a function of the water mass flow density. Below a specific surface temperature T L , film boiling becomes unstable and the HTC shows a strong dependence on temperature (Leidenfrost effect). The HTC was measured by an automated cooling test stand (instationary method). Compared to the

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... s state-of-the-art, an additional temperature dependency in the high temperature regime was found. A new analytic fit formula for the dependence of the heat transfer coefficient on temperature and water impact density is proposed and discussed. Spray water cooling of steel materials at temperature levels above 1000K introduces additional effects due to the formation of oxide layers (scale). These effects and experiments under scale formation conditions will be presented and discussed.