Patent ID: 8757124

Claim:
A movable wall member in form of an exhaust valve spindle for an internal combustion engine, which exhaust valve spindle comprises: a base portion of an austenitic, stainless steel having a carbon-content in the range from 0.15 to 0.35% by weight, and an outer portion forming a surface of the wall member for facing a combustion chamber, which outer portion is of a hot-corrosion-resistant alloy, which is nickel-based, chromium-based or cobalt-based, wherein at least one buffer layer is of an alloy and is located in between the base portion of austenitic, stainless steel and the outer portion, wherein the alloy of the buffer layer has an alloy composition different from the austenitic, stainless steel of the base portion and different from the hot-corrosion-resistant alloy of the outer portion, wherein the alloy of the buffer layer comprises from 0% to at the most 0.09% C in percent by weight of the buffer layer, wherein the buffer layer has a thickness of at least 1.5 mm, and wherein the buffer layer restricts diffusion of carbon from the austenitic, stainless steel of the base portion to the hot-corrosion-resistant alloy of the outer portion.