Thermal fatigue behaviour of Fe-1.7C-11.3Cr-1.9Ni-1.2Mo roller steel in temperature range 500–700 °C

Mechanisms of Oxidation Degradation of Cr12 Roller Steel during Thermal Fatigue Tests

“…Conductive heating and water cooling by the borehole sample were carried out cyclically according to a temperature program that replicates the conditions obtained on the roll surface during hot rolling. A detailed description of the test rig is given in [5], while detailed qualitative and quantitative properties of thermal fatigue resistance for the same material are given in [6]. After the thermal fatigue test, the working lengths of each specimen were first cut in the axial direction through the center and one half also in the radial direction for microscopy.…”

“…High manufacturing costs make any attempts to increase the operating time of the rolls and improve the surface quality of the rolled products enticing [2][3][4]. The oxidation process of rolls has a strong influence on the complex degradation process of the roll surface layer [4][5][6][7][8][9][10][11][12][13]. The degradation of the roller surface is related to the microstructure, the temperature and the thermal stresses acting on it.…”

“…It is generally very complex, as temperature, time, environmental conditions and microstructure are intertwined [3,. The oxidation behavior of roller material at high temperatures was investigated by oxidation studies [4,15,22,23,28,[34][35][36][37][38], tribological tests [3,[9][10][11]14,16,25,26,33,35,[39][40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57] and thermal fatigue tests [5,6,12,[29][30][31]. The tribological tests were performed with disc-on-disc tests [3,[9][10][11]…”

“…In addition, different oxidation rates were observed for the different carbide types in the matrix, which is the basis for the formation of relatively small oxidation tongues. In the studies [5,6,12,[29][30][31] thermal fatigue tests were used to demonstrate that oxidation accelerates crack growth and other degradation processes (i.e., chipping and spalling). However, the oxidation penetration was not investigated.…”

“…Conditions found in the laboratory often do not reproduce the severe conditions found in industry. Our thermal fatigue testing setup [5,6], has the advantage of an extremely precise temperature control with computer controlled heating and cooling, resulting in a constant temperature field of all cycles from the first to the last. This enabled the repeatability of thermal fatigue tests, wherein quantitative analysis of degradation by thermal cycles showed that oxidation penetration can have a significant influence on the degradation progress of the roller material surface.…”