The martempering process produces thin martensitic stainless steel strips and is widely used for production of valve- and spring steel. Industrial trials were conducted in collaboration with Böhler Uddeholm Precision Strip, Munkfors, Sweden. These trials suggested that the quenching step is critical to control, in order to reduce uneven temperature gradients which will lead to distortions or unevenness. To investigate this, computational modelling of the temperature was performed to estimate the current situation for the conventional martempering process based on physical theories together with Comsol Multiphysics and using a steady state modeling approach. The model boundary conditions were based upon temperature measurements in the real process. Furthermore, the strip was modelled as it comes out of the heating furnace, which is filled with hydrogen gas and continues into a molten lead-bismuth bath for quenching. Thus, the temperature profile was obtained for the strip as well as its surroundings; The results show that a better insight of the martempering line could be achieved. The model results can be used to investigate disturbances in the normal operation. Furthermore, the temperature profiles can be used to optimize the process and possibly to reduce the energy consumption.