A. Neidel, T. Gädicke, M. Giller, S. Riesenbeck
February 4, 2020
A novel tip of a fuel gasification burner, designed-to-SLM (Selective Laser Melting) and made by SLM, was introduced by the client. This component failed prematurely by cracking at the cooled tip. The metallurgical cause of the failure was overheating due to blocked cooling passages, probably as a result of contaminated cooling water, leading to corrosion in the non-stainless piping systems upstream of the burner. Corrosion products, mainly iron oxides, spalled off said non-stainless components, causing blockages in the intricate cooling cavities of the AM-built burner tip. This lead to excessive thermal overload, reaching the melting temperature of the alloy at the burner tip. As a result, the subject burner tip failed by TMF cracking. Neither manufacturing nor design flaws were identified in the course of this failure investigation. It is speculated that the subject component will perform well if cooled properly. The root cause of the failure is the operation of the cooling water system of the subject burner that allowed loose corrosion products to form and to enter the burner tip.