Testing and analysis of X39CrMo17-1 steel properties

•Experimentally obtained material properties.•Creep and relaxation phenomena and their modeling.•Engineering fracture toughness assessment. Experimental tests have been carried out to obtain data on the behavior of martensitic stainless steel X39CrMo17-1 (AISI 420RM; 1.4122) under different environmental conditions. This article provides an insight into experimental results related to mechanical properties, tension creep and relaxation phenomena as well as Charpy impact energy of considered material. Modeling of some creep and relaxation curves as well as an assessment of fracture toughness based on Charpy impact energy can be also found in this paper. An analytical approach for creep deformation analysis is proposed. Due to survey results, we may conclude that the investigated material has outstanding mechanical properties and sufficient resistance to creep when the applied load is low in relation to its yield strength at prescribed temperature.