This dissertation addresses the development of a new process for manufacturing longitudinal seam welded pipes whereby the inner weld seam is galvanised on a pipe mill in a continuous process in such a manner that metallurgical adhesion between the zinc and the iron is produced by the application of suitable additives, and a consistent zinc layer with ideal formability is created. Process-relevant investigations led to the depiction of the required temperature level for the new methodology during pipe manufacture, and the study of the relevant literature supplied information on interior galvanising requirements and the interaction and metallurgical reactions of the materials to one another. The experiments were performed by means of differential scanning calorimetry, an attached mass spectrometer and high-temperature equipment for x-ray structure analysis. These supplied significant findings in relation to the temperature dependence of the reactions and the reaction products formed which can be of decisive importance for the wetting conditions. These fundamental investigations were accompanied by experiments on self-developed pilot plants in order to create a comprehensive understanding of the process by means of observations and material investigations. Through suitable adaptation of the composition of the additives, the quantity used and the correct temperature control, a way was found to minimise the reaction products. The approach described also permitted possible difficulties within the process sequences with regard to wetting to be defined and solved for interior galvanising and highlighted new possibilities for process optimisation. This particularly includes the development of the additives required for wetting. A completely new way was found by means of the experiments. The collected findings were transferred to the company and led to the continuous production of internally galvanised pipes under economic conditions and also of saleable quality.