Processing, structure, and properties of a rolled, ultrahigh-carbon steel plate exhibiting a damask pattern

A plate of ultrahigh-carbon steel (UHCS) was processed by hot and warm rolling, according to the Wadsworth–Sherby mechanism, to produce damask surface markings. The surface markings produced by this industrial processing method are similar to those of historical Damascus steels, which are also of hypereutectoid composition. The microstructure of the UHCS with damask contains fine, spheroidized carbides and a discontinuous network of proeutectoid carbides along former-austenite grain boundaries, which give rise to a surface pattern visible with the unaided eye. Tensile tests at room temperature measured tensile strengths and ductilities, which depend on sample orientation relative to the rolling direction of the plate. Hot and warm rolling causes a directional microstructure, giving rise to both an elongated, directional damask pattern and a directional dependence for strength and ductility. A maximum tensile ductility of 10.2% was measured at 45° relative to the rolling direction. The plate material was subjected to heat treatments creating pearlitic and martensitic microstructures, which retain visible damask patterns.