Hot compression testing of mild steel industrial reheat furnace scale

The deformation of reheat furnace scale, formed on mild steel slabs in an industrial reheat furnace, was investigated using a high temperature compression test technique, over the temperature range of 650–850°C. Strain was nominally 30% for all tests, conducted at two strain rates, 0.1 and 1.0 s −1 . The mill scale samples were 6mm thick, ground to obtain cylindrical compression test pieces. The test parameters were chosen to demonstrate the deformation behaviour of a porous scale at temperatures similar to the entry conditions to the finishing stands of a hot strip mill. Oxide scales are generally assumed to be brittle at these temperatures. In the present tests the scale deformed in a linear‐like elastic/plastic manner under these conditions. Although cracking occurred, the samples remained intact as the deformation proceeded. Below 650°C the scale was crushed to a powder immediately after the start of the compression process.