Prakt. Met. Sonderband 50 (2016) 19 
e.g. by aqueous 
must concede that 
or this particular 
g. through proper 
by aqueous elec- 
1.4031, violated 
. recurring. In the 
ies. It is therefore 
cond, the material 
particular applica- 
cat treatments are Fig. 6: Secondary chromium carbides on grain boundaries 
ensitive to contact 
sion Fig. 7: Scanning electron microfractograph of fracture surface. Interganular attack as evidenced by 100 % intergranular 
fracture 
3 Thermal Overload Failures — TMF Failure of a Y-shaped Pipe 
A particular heavy-duty gas turbine burner, used in a burner rig test, featured a Y-shaped fuel gas 
feed pipe. The Y-pipe was made by non-conventional production, in an attempt to test the 
component and its specialty manufacturing process in an environment that simulates service 
conditions without causing collateral damage to other engine components in case of failure. The Y- 
pipe was produced by additive manufacturing (AM), using a process that is known as selective laser 
melting (SLM). This process is well suited for complex parts due to its advantageous geometrical 
freedom. It is known to have been used for intricate piping systems before. However, the Y-shaped 
| pipe failed by thermal-mechanical fatigue cracking (TMF) [7] - [22]. 
mnular corrosion