Materials and Corrosion 2012. 63. No. 1 Mechanical degradation failure on leakage of titanium tubes 21 a 9 123456 mteulmmmuilulllluuluullmlmlil X35 500Nm 24/DEC/0S B c) Figure 5. External appearances of the ruptures on leaked tube clogge by sediment: (a) locations of ruptures, (b)deformed inside wall piece of tube material had already directly dissociated from the tube wall, rather than being gradually flaked away. 3.2.2 Tube clogged by seashell Rupture on this tube clogged by a seashell was located approximately omm off the inlet, as shown in Fig. 7a, ie, it was buried inside the 78mm-thick Ti/carbon steel tube sheet This rupture was generated by the erosion of seawater containing sediments on x156168 24∠DEC/85 logging position of the seashell and its failure morphology looked ke actinomorphous, as seen in Fig. 7b. Also, it should be Figure 6 SEM morphologies of the rupture B on the inside wall particularly pointed out that, on the inside wall of the 9X 5mm (a) total morphology, (b) crack, and (c) dissociation tinomorphous rupture, the erosion traces on the three tips (named A, B, and C)were all in the same actinomorphous shape too Then, the three tips were further detected under SEM. After ruptures and a 250 mm-long crack, seen in Fig. 9a. After cutting summarizing, traces representing four different mechanical off, it was displayed in Fig. 9b that rubber stripes were rolled and degradation mechanisms were observed, including abrasive attached around the entire circumference of the tube inside wall. erosion(Fig. 8a), flaking away(Fig. 8b), impact(Fig. 8c), and As a result, the inside wall was seriously deformed due to the cracking(Fig. 8d), more diverse than the rupture on the leaked pressing effect from the rubber(Fig. 9c), and the crimples were metrically on the two sides of the ruptures. As for the other tube, long indentations instead of crimples caused by pressing 3. 2.3 Tube clogged by rubber debris effect from the rubber stripes were on the inside wall of the tube Two leaked tubes that were both clogged by rubber debris were seen in Fig. 9d, which means the rubber stripes were fully sampled. The first tube was encountered with three round stretched rather than being rolled. www.matcorr.com o 2012 WILEY-VCH Verlag GmbH& Co KGaA, Weinheimpiece of tube material had already directly dissociated from the tube wall, rather than being gradually flaked away. 3.2.2 Tube clogged by seashell Rupture on this tube clogged by a seashell was located approximately 40mm off the inlet, as shown in Fig. 7a, i.e., it was buried inside the 78 mm-thick Ti/carbon steel tube sheet. This rupture was generated by the erosion of seawater containing sediments on clogging position of the seashell and its failure morphology looked like actinomorphous, as seen in Fig. 7b. Also, it should be particularly pointed out that, on the inside wall of the 9 T 5 mm2 actinomorphous rupture, the erosion traces on the three tips (named A, B, and C) were all in the same actinomorphous shape too. Then, the three tips were further detected under SEM. After summarizing, traces representing four different mechanical degradation mechanisms were observed, including abrasive erosion (Fig. 8a), flaking away (Fig. 8b), impact (Fig. 8c), and cracking (Fig. 8d), more diverse than the rupture on the leaked tube clogged by sediments. 3.2.3 Tube clogged by rubber debris Two leaked tubes that were both clogged by rubber debris were sampled. The first tube was encountered with three round ruptures and a 250 mm-long crack, seen in Fig. 9a. After cutting off, it was displayed in Fig. 9b that rubber stripes were rolled and attached around the entire circumference of the tube inside wall. As a result, the inside wall was seriously deformed due to the pressing effect from the rubber (Fig. 9c), and the crimples were symmetrically on the two sides of the ruptures. As for the other tube, long indentations instead of crimples caused by pressing effect from the rubber stripes were on the inside wall of the tube, seen in Fig. 9d, which means the rubber stripes were fully stretched rather than being rolled. Materials and Corrosion 2012, 63, No. 1 Mechanical degradation failure on leakage of titanium tubes 21 Figure 5. External appearances of the ruptures on leaked tube clogged by sediment: (a) locations of ruptures, (b) deformed inside wall Figure 6. SEM morphologies of the rupture B on the inside wall: (a) total morphology, (b) crack, and (c) dissociation www.matcorr.com
2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim