PSI - Issue 36

Valentin Ilyushenko et al. / Procedia Structural Integrity 36 (2022) 100–105 4 V. Ilyushenko, T. Maydanchuk, E. Lukianchenko, S. Kozulin, S. Marynenko / Structural Integrity Procedia 00 (2021) 000 – 000 3. Experimental results Metallographic studies of metal samples cut from the end (working) and tail parts of the chamber, carried out by Ilyushenko et al. (2019), showed a coarse-crystalline structure, which is characteristic of cast copper (Fig. 4 a, b). 103

а

b

c

d

e

Fig. 4. Macrostructure of metal from the end (a) and tail (b) parts of the chamber, and microcracks (c, d, e) of various shapes and sizes in the working part of the chamber, x100.

On the macrosection of the sample from the end part, a network of cracks along the grain boundaries is clearly visible. These cracks originate from the metal surface and propagate into copper to a depth of 10 mm (Fig. 4 a), while they have different shapes and sizes (Fig. 4 a, c, d, e), as demonstrated by Ilyushenko et al. (2019). At the same time, on templates from the tail section no such cracks are observed in the chamber (Fig. 4 b). Based on the results of the chemical (using the X-Ray Spectometer: X`Unique II X-ray fluorescence analyzer from Philips) and gas (using the RH-402 and RO-316 analyzers from Leco) analyses, shown in Table 1, the studied copper, according to the data of Osintsev and Fedorov (2004) can be referred to as deoxidized grade ASTM C12900. At the same time, as the analysis showed, the presence of up to 0.0033% selenium was found in the metal under study. As follows from Table 1, the content of oxygen and hydrogen in the samples cut from the end and tail parts is practically the same.

Table 1. Chemical composition and gas analysis of the investigated copper Material Chemical composition, wt. %

Gas content

Se

(Cast copper)

P

Fe

Zn

Cu

[O], wt. %

[H], wt. %

0.00034 0.00047 0.00031 0.00025

From the tail

0.044

0.04

0.015

0.0033

Balance

0.0101

From the working end part 0.041

0.045

0.012

0.0031

Balance

0.0094

The results of mechanical tests of the investigated copper at different temperatures are shown in Table 2.