Development of a novel temperature indicator

Abstract

The δ-ferrite transformation characteristics of a series of specially made experimental duplex stainless steels have been studied. The ferrite content of these steels changes with time and temperature and this special property is used to develop an effective temperature indicator, i.e. if the time of exposure is known the change in ferrite content in these steels can be used to indicate the average temperature over this period. A Feritscope is used to measure the ferrite content, a measurement which can be performed on site in a matter of seconds. Further advantages of using stainless steel are that it is corrosion resistant, tough, ductile and only a small sample (e.g. 6 mm diameter × 2 mm thick) is required for reproducible measurement.