Abstract Modern thermal and thermochemical treatment of steels is a rapidly growing research area. Thermochemical processes are researched, designed, optimized, and controlled by computer-aided methods. The goal of the present paper is to provide a comprehensive state-of-the-art review and to analyze the critical mass of knowledge in the field of modeling methods to describe the interactions between the processing, microstructure and postoperative properties of the treated material. This article briefly discusses modern low-pressure thermochemical processes to describe the difficulties in modeling their non-equilibrium nature and transient states that occur in the course of the processes. A synthetic review of modeling methods, in particular, artificial intelligence methods, is presented to investigate low-pressure thermochemical processes. The opportunities and dangers associated with these methods are also analyzed.