242 Prakt. Met. Sonderband 46 (2014) 
All metallographic investigated material states are shown in Tab. 2. The temperature of the 2.2.3 SH 
solution annealing of base material was 1175 °C for 1 h with quenching in water. Base 
material was investigated at first in solution annealed condition (A1) and the weld metal in To char: 
as-welded state (W1). Then the welded joint was heat treated at 980 °C for 3 h and the carried ¢ 
area of BM (A2) and WM (W2) was examined. Short-term creep tests at 700 °C were Cross we 
performed on cross weld specimens in as-welded and heat treated condition and after that weld he: 
the microstructure investigations were carried out in different areas of specimen according 
to Tab. 2. 
3. RES 
Tab. 2: Investigated states of Alloy 617 
31. M 
Alloy 617 
State - : —_— 
~ a Materials condition The resı 
A Base material, solution annealed as-welde 
Wi1 Weld metal, as-welded material, 
m DI - — LS in the de 
A2 | Base material, solution annealed + 980 °C for 3 h and the 
wz | Weld metal, as-welded + 980 °C for 3h Cross wi 
A3 Base material, solution annealed + 700 °C at 310 MPa location 
W3 Weld metal, as-welded + 700 °C at 310 MPa 
Ad _Base material, solution annealed + 980 °C for 3 h+700 °C at 310 MPa 
w4 Weld metal, as-welded + 980 °C for 3 h+ 700 °C at 310 MPa 
2.2 MICROSTRUCTURE AND MECHANICAL TESTS 
2.2.1 OPTICAL MICROSCOPY (OM) 
Sample preparation for the light optical characterization includes wet grinding by SiC 
abrasive paper with 180-, 320-, 500-, 800- and 1200-grit and polishing with diamond paste 
with 15 pm-, 6 ym- and 1 pm-grit for 5 min respectively. Afterwards the samples were 
polished (vibratory polisher) with diamond paste (1 pm) and SiO, (0.05 pm) and etched in 
10% aqueous oxalic acid, in order to reveal the grain size, morphology, and presence of 
second-phase precipitates. For the light-optical observations the light microscope 
Aristomet from Leica was used. 
3.22 M 
2.2.2 TRANSMISSION ELECTRON MICROSCOPY (TEM) 3.2.1 ME 
For the determination of the precipitate population the specimens were investigated by The har 
Transmission Electron Microscope (TEM). For these analyses a microscope JEOL JEM sections 
2000 FX was used. For the investigation of the precipitation sizes and density metal foils compare 
were used. The identification of particles was done by Selected Area Diffraction Pattern 329, W3 
(SADP) and Energy-Dispersive X-ray spectroscopy (EDX). 339, WA 
The size, size distribution, and other geometric parameters of the particles were conditior 
determined by image analysis. For this purpose, the program ImageJ was used. As heat tre: 
essential geometric parameters of a particle a diameter of the circle of equal area welded j 
(equivalence circuit) is used for further discussion. Up to 10 images were evaluated at a state cor 
magnification from 10,000 to 150,000 for each state. of type 
str