• The damage in 800 series materials of reformer outlet components from 7 petrochemical and chemical fertilizer enterprises mainly occured on the base metal, and the failure modes were bulging, cracking and fracturing, and the failure mechanisms were creep and carburizing, respectively. • Factors such as grain size, metal wall temperature and stress concentration significantly determine the safe service life of 800 series alloy materials for outlet components of reformer such as pigtail tube, outlet tube, stiffener nozzle and collection tube. • The possibility of creep damage and carburization damage of 800 series components can be reduced by upgrading the material to 800HT, controlling the grain size to level 2–5, avoiding low load rate and medium bias flow in the process. To investigate the failure of 800 series materials from the furnace tube outlet components of the reformers, the test devices such as metallographic microscope, scanning electron microscope, carburizing detector and high temperature endurance testing machine were adopted. The failure mode and failure mechanism of 800 series materials for outlet components of reformer such as pig tail pipe, outlet pipe, stiffener joint and collection tube, which had been in service for 1–11 years from 7 petrochemical and chemical fertilizer enterprises were analyzed. The results suggest that the damage of 800 series materials from reformer outlet components in 7 petrochemical and chemical fertilizer enterprises mainly occurred on the base metal. The failure modes included bulging, cracking and fracture, and the principal failure mechanisms were creep and carburizing, respectively. The main factors affecting the failure of 800 series materials in the tube outlet components of reformer were discussed with respect to grain size, metal temperature and stress concentration. Consequently, multiple suggestions were given to avoid premature damage and failure of such components. [ABSTRACT FROM AUTHOR]