This paper presents a failure analysis performed to investigate cracking observed in a weld joint in the shell of a reheater. Thorough investigation using visual inspection, chemical analyses, metallographic examinations, hardness testing, and creep analysis showed that the weld joint failed by creep. The shell was fabricated from the heat-resistant alloy, Incoloy 800H, and had been in service for 16 years. The shell was exposed to superheated steam at 720 °C. Corrective actions were proposed to repair the shell and prevent recurrence of cracking.