Microstructure and properties of violin strings made of metastable austenitic steel

Abstract

The strings of musical instruments are frequently made of stainless steel wires. Samples taken from consecutive steps of wire drawing showed the kinetics of deformation-induced martensite formation from metastable austenitic feedstock. Stacking fault and twin formation were described by transmission electron microscopy. The progress of martensitic transformation was accompanied by an increase in defect density and in micro-strains determined by synchrotron X-ray diffraction. The initial fall in the Young's modulus determined by tensile tests was accompanied by a drastic reduction in domain size and in grain diameter. Texture and phase transformation at the wire surface were measured by X-ray diffraction. The deformation-induced martensite formation has been described in its nucleation, growth and saturation stages. These three stages were defined by the correlation of the evolution of the microstructural features in the course of the wire drawing process.