AbstractAn investigation of 2·25Cr–1Mo–0·1C weld metal has been carried out using atom probe field ion microscopy. The weld metal had a microstructure consisting of bainitic ferrite and retained austenite, but no cementite. The carbon concentration at the austenite/ferrite interface was found to change abruptly, whereas the concentration of substitutional alloying elements was the same in both phases. No enrichment could be found at the interface.MST/1444