Cooling "red-hot" Steel Ring

[Cherry]

I am trying to cool a "red-hot" steel ring to room temperature. Water is chosen to be the coolant and only the dimensions of the ring and the travelled height (i.e.5 m) are given. Adopting the lump capacitance technique, I would like to determine the rate of heat loss but am having difficulty ascertaining the heat convection coefficient, h.

Steel ring T=850 deg C; Coolant 25 deg C; outer diameter of ring=0.15 m; inner diameter of ring=0.14 m; height of ring=0.02m; distance travelled=5m