LABORATORY RESEARCHES UPON THE THERMAL FATIGUE OF THE ORGANS OF MACHINES IN MOVEMENT OF ROTATION, IN VARIABLE TEMPERATURE MEDIUMS

The researches of durability in the exploitation of cast-iron rolls define experimentally an important chapter from the thermal fatigue of the organs of machines in the movement of rotation, in variable temperature mediums. The researches on the durability in exploitation of hot rolling mill rolls represent an important scientific and economical issue. This paper presents original experimental equipment by the help of which the durability of hot rolling mills can be studied. This experimental equipment permits the evaluation of exploitation durability for hot rolls by studying the thermal fatigue phenomenon which appears in the case of machine components. The exploitation durability is evaluated through thermal fatigue cycles up to crack point due to thermal fatigue for each condition and each type of studied material. The study represents a detailed approach of the influence of various technological factors on the durability in exploitation of rolling mill rolls made of different steel and pig iron grades and suggests solutions meant to increase the durability of the rolls in exploitation.