Microstructural analysis as the indicator for suitability of weld repairing of the heat resistant Cr - Ni steel
Abstract
Metallurgical evaluation was performed on a fractured column tube of the reformer furnace in an ammonia plant. The tubes were manufactured from centrifugally cast heat resistant steel HK 40. Optical and scanning electron microscope (SEM) were used for microstructural and fracture analysis. For composition determination of the microconstituents energy dispersive X ray spectroscopy (EDS) was used. To evaluate mechanical properties, hardness and microhardness measurements were performed. Investigations based on the microstructural features with the idea to indicate suitability of weld repair of the column were performed in this study. It was observed that the crack initiation, caused by oxidation/corrosion and thermal stresses induced by temperature gradient, appeared in the inner side of the tube wall and propagation occurred along grain boundaries. The results clearly showed the presence of an irregular microstructure which contributed to crack propagation through the tube wall. An occu...rrence of precipitated needle-shaped carbides/carbonitrides and brittle a phase was also identified in the microstructure. Results of the microstructural and fracture analysis clearly indicate that reformer furnace columns made of heat resistant steel HK 40 were unsuitable for weld repair.
Keywords:
Weld repair / Steel HK40 / Mrostructural evaluation / Fracture analysisSource:
Revista de Metalurgia, 2010, 46, 4, 320-330Publisher:
- Consejo Superior Investigaciones Cientificas-Csic, Madrid
Funding / projects:
DOI: 10.3989/revmetalm.0939
ISSN: 0034-8570
WoS: 000287434100003
Scopus: 2-s2.0-78349241103
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Institution/Community
Institut za ispitivanje materijalaTY - JOUR AU - Odanović, Zoran AU - Blačić, Ivo AU - Vracarić, D. AU - Grabulov, Vencislav AU - Burzić, Meri AU - Katavić, Boris PY - 2010 UR - http://rims.institutims.rs/handle/123456789/113 AB - Metallurgical evaluation was performed on a fractured column tube of the reformer furnace in an ammonia plant. The tubes were manufactured from centrifugally cast heat resistant steel HK 40. Optical and scanning electron microscope (SEM) were used for microstructural and fracture analysis. For composition determination of the microconstituents energy dispersive X ray spectroscopy (EDS) was used. To evaluate mechanical properties, hardness and microhardness measurements were performed. Investigations based on the microstructural features with the idea to indicate suitability of weld repair of the column were performed in this study. It was observed that the crack initiation, caused by oxidation/corrosion and thermal stresses induced by temperature gradient, appeared in the inner side of the tube wall and propagation occurred along grain boundaries. The results clearly showed the presence of an irregular microstructure which contributed to crack propagation through the tube wall. An occurrence of precipitated needle-shaped carbides/carbonitrides and brittle a phase was also identified in the microstructure. Results of the microstructural and fracture analysis clearly indicate that reformer furnace columns made of heat resistant steel HK 40 were unsuitable for weld repair. PB - Consejo Superior Investigaciones Cientificas-Csic, Madrid T2 - Revista de Metalurgia T1 - Microstructural analysis as the indicator for suitability of weld repairing of the heat resistant Cr - Ni steel EP - 330 IS - 4 SP - 320 VL - 46 DO - 10.3989/revmetalm.0939 ER -
@article{ author = "Odanović, Zoran and Blačić, Ivo and Vracarić, D. and Grabulov, Vencislav and Burzić, Meri and Katavić, Boris", year = "2010", abstract = "Metallurgical evaluation was performed on a fractured column tube of the reformer furnace in an ammonia plant. The tubes were manufactured from centrifugally cast heat resistant steel HK 40. Optical and scanning electron microscope (SEM) were used for microstructural and fracture analysis. For composition determination of the microconstituents energy dispersive X ray spectroscopy (EDS) was used. To evaluate mechanical properties, hardness and microhardness measurements were performed. Investigations based on the microstructural features with the idea to indicate suitability of weld repair of the column were performed in this study. It was observed that the crack initiation, caused by oxidation/corrosion and thermal stresses induced by temperature gradient, appeared in the inner side of the tube wall and propagation occurred along grain boundaries. The results clearly showed the presence of an irregular microstructure which contributed to crack propagation through the tube wall. An occurrence of precipitated needle-shaped carbides/carbonitrides and brittle a phase was also identified in the microstructure. Results of the microstructural and fracture analysis clearly indicate that reformer furnace columns made of heat resistant steel HK 40 were unsuitable for weld repair.", publisher = "Consejo Superior Investigaciones Cientificas-Csic, Madrid", journal = "Revista de Metalurgia", title = "Microstructural analysis as the indicator for suitability of weld repairing of the heat resistant Cr - Ni steel", pages = "330-320", number = "4", volume = "46", doi = "10.3989/revmetalm.0939" }
Odanović, Z., Blačić, I., Vracarić, D., Grabulov, V., Burzić, M.,& Katavić, B.. (2010). Microstructural analysis as the indicator for suitability of weld repairing of the heat resistant Cr - Ni steel. in Revista de Metalurgia Consejo Superior Investigaciones Cientificas-Csic, Madrid., 46(4), 320-330. https://doi.org/10.3989/revmetalm.0939
Odanović Z, Blačić I, Vracarić D, Grabulov V, Burzić M, Katavić B. Microstructural analysis as the indicator for suitability of weld repairing of the heat resistant Cr - Ni steel. in Revista de Metalurgia. 2010;46(4):320-330. doi:10.3989/revmetalm.0939 .
Odanović, Zoran, Blačić, Ivo, Vracarić, D., Grabulov, Vencislav, Burzić, Meri, Katavić, Boris, "Microstructural analysis as the indicator for suitability of weld repairing of the heat resistant Cr - Ni steel" in Revista de Metalurgia, 46, no. 4 (2010):320-330, https://doi.org/10.3989/revmetalm.0939 . .