Hot Compression Test of Heat Resistant Steel

This article deals with the analysis of formability of heat resistant steel type 9Cr-1Mo by physical laboratory simulation - hot compression test. The 9Cr-1Mo steel belongs to modern 9%Cr tempered martensitic steel for high-temperature applications in advanced thermal power plants. The shape of the sample was defined based on numerical simulations. The laboratory simulation of forming process called physical simulation - specifically hot compression test was realized in the temperature range from 500 to 950°C and total deformation in the range from 39 to 52%. Cracks formed during hot compression test in the notches are assessed. Subsequently, the relation between the compression temperature, strain, and crack length was defined. The suitable workability corresponds to the temperature range 650-900°C, it agrees with results of numerical simulations. At a temperature of 900°C there is marginal relative deformation without rupture ε =39.9%, which corresponds to the value according to simulations NCL criteria 0.501.