A process for the preparation of hydrogen and carbon monoxide containing gas from a gaseous hydrocarbon feedstock by performing the following steps: (a) partial oxidation of part of the feedstock thereby obtaining a first gaseous mixture of hydrogen and carbon monoxide; and, (b) catalytic steam reforming of part of the gaseous feedstock in a Convective Steam Reformer having a tubular reactor provided with one or more tubes containing a reforming catalyst, wherein the exterior of the tubes of the tubular reactor is used to cool the hot gas as obtained in step (a) and wherein the exterior of the tubes is a metal alloy surface having between 0 wt % and 20 wt % iron.