Movable wall member in the form of an exhaust valve spindle or a piston in an internal combustion engine

A member having having a side, which faces a combustion chamber and is provided with a hot-corrosion-resistant material,

• which corrosion-resistant material in terms of percent by weight and apart from common impurities and inevitable residual amounts of deoxidizing components comprises from 38 to 75% Cr and a number of the following components from 0 to 0.15% C, from 0 to 1.5% Si, from 0 to 1.0% Mn, from 0 to 0.2% B, from 0 to 5.0% Fe, from 0 to 1.0% Mg, from 0 to 2.5% Al, from 0 to 2.0% Ti, from 0 to 8.0% Co, from 0 to 3.0% Nb, and a balance of Ni, aggregate contents of Al and Ti amounting at the most to 4.0%, and aggregate contents of Fe and Co amounting at the most to 8.0%, and aggregate contents of Ni and Co amounting at the least to 25%,
• said corrosion-resistant material being made from a particulate starting material which by a HIP process has been unified to a coherent material substantially without melting the starting material, and
• said corrosion-resistant material having a hardness of less than 310 HV measured at approximately 20° C. after the material has been heated to a temperature within the range of 550-850° C. for more than 400 hours.

A hot-corrosion-resistant material, which in terms of percent by weight and apart from common impurities and inevitable residual amounts of deoxidizing components comprises from 38 to 75% Cr and a number of the following components from 0 to 0.15% C, from 0 to 1.5% Si, from 0 to 1.0% Mn, from 0 to 0.2% B, from 0 to 5.0% Fe, from 0 to 1.0% Mg, from 0 to 2.5% Al, from 0 to 2.0% Ti, from 0 to 8.0% Co, from 0 to 3.0% Nb and a balance of Ni, aggregate contents of Al and Ti amounting at the most to 4.0%, and aggregate contents of Fe and Co amounting at the most to 8.0%, and aggregate contents of Ni and Co amounting at the least to 25%,

• said corrosion-resistant material being made from a particulate starting material which by a HIP process has been unified to a coherent material substantially without melting the starting material, and
• said corrosion-resistant material having a hardness of less than 310 HV measured at approximately 20° C. after the material has been heated to a temperature within the range of 550-850° C. for more than 400 hours.