Abstract
A splitting phenomenon in the weld zone of the radiator nipples was encountered after a threading operation. During the failure analysis, some oxide traces were macroscopically observed on the surfaces of unthreaded nipples. Subsequent scanning electron microscopy–x-ray spectrometer (SEM–EDS) examination through the surfaces of the unthreaded nipples and as-pickled steel sheet coupons that were used for nipple manufacturing revealed that the oxide traces were hot-rolling scale residuals. However, none of the traces of scale residuals were encountered on the cross sections of weld zone of unthreaded nipple samples. Contrarily, some cracks and inclusion residuals were observed through the interface between the protrusion and weld zone. EDS analysis and optical microscopy affirmed the presence of MnS-type inclusions. The same kind of inclusions was also observed when one of the unthreaded nipples was intentionally separated through the weld zone. In conclusion, the main cause for the failure was determined to be the adverse effect that the MnS inclusions in the steel had on the material ductility.
Similar content being viewed by others
References
Colangelo V.J., Heiser F.A.: Analysis of Metallurgical Failures. pp. 2–3. Wiley-Interscience Publication, John Wiley & Sons (1974).
ASM Handbook, vol. 6, Welding, Brazing and Soldering, pp. 833–850. ASM International (1993).
Welding Handbook, 4th edn., section 2, Gas, Arc and Resistance Welding Processes, Phillips, A.L. (ed.), pp.31.2–31.6. American Welding Society (1962).
Honeycombe, R.W.K., Bhadeshia, H.K.D.H.: Steels, Microstructures and Properties, 2nd edn, pp. 236–239. Gray Publishing (1995).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Elkoca, O., Cengizler, H. Failure of Welded Radiator Nipples Caused by Nonmetallic Inclusions. J Fail. Anal. and Preven. 7, 414–418 (2007). https://doi.org/10.1007/s11668-007-9073-x
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11668-007-9073-x