Please visit Boiler Tube Research (Super-Heater) Part 2 for previous explanation.
Observation of the micro-structure is required for viewing the phase change or is there a change of micro-structure that occur during pipeline use and also to prove that a broken pipe caused by erosion only. Samples taken from pipes that are experiencing thinning of the outer walls and the surface shape of a wave (Figure 2.7). Photos of specimens and the resulting micro-structure can be seen in Figure 2.8 up to 2.11.
The hardness test results on free damage area and the damaged area can be seen in Table 2.6.
From the results of analysis of micro-structure and test photos of hardness test in an area that experienced depletion can be concluded that:
1. Damage occurs not because of the influence of thermal deformation of plastic or, since there is no change in the micro-structure occurs significantly.
2. test results of violence in an area that is experiencing thinning a bit down.
3. macro photos Of looks that the thinning of the walls of tubes happens because the process of erosion.