Express evaluation of temperature range of steel blue brittleness

A brief analysis of the blue brittleness temperature range of structural steels and the reasons for its occurrence has been carried out. It is noted that blue brittleness causes a change in all mechanical characteristics of steel. In particular, the strength characteristics increase, and the plasticity characteristics decrease in a narrow temperature zone of blue brittleness. It was established that hardness changed similarly to strength and can be used as a diagnostic parameter to identify the temperature range of blue brittleness. For three grades of structural steels, experiments were carried out to identify the temperature range of blue brittleness by tension of samples at various temperatures. A technique for express detection of the blue brittleness temperature range by changing the Brinell hardness determined by instrumented indentation is proposed. The technique eliminates the need to manufacture samples and saves material and labor costs.