| In STS303 austenitic stainless steel, the effects of chemical composition, boron addition and deformation condition on hot ductility and/or machinability, were investigated. Hot-tensile test was carried out at the temperature range of 950℃∼1150℃. Optical microscopy and scanning electron microscopy were used to investigate the occurrence of cracks during hot deformation. Also the shape of chips during machining, was investigated at the turning speed of 50m/min-200m/min with 1.0, 1.5, 2.0㎜ in the depth of cut for selected compositions. Hot ductility of STS303 is increased with increasing the Mn/S ratio, while the total oxygen content has little influence on hot ductility. Boron added steels showed a superior hot ductility and s machinability equivalent to the type of 303 austenitic stainless steel. |
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