• Amir
• Harpreet Singh
• Mohd Zahid Saifi

As continuous up gradation and advancement in continuous galvanizing technology which is resulting improvements in quality of surface of hot dip galvanized and galvanized coatings, producing entirely blemish-free coatings which still stand out with challenging task. An in-depth study of these defects helps in identifying and employing prompt remedial measures to eliminate there occurrences. This paper researched by me reviews the commonly visible defects in continuously galvanized pipes products with their characteristics as studied by metallographic techniques and the means of eliminating them. Although almost every tiny defect in a galvanized coating may look like a grey spot, Less coating , ash, Black spots, peel off, lumps, Dross dimples,&Excess zinc are only a small portion of the defects found in hot dip galvanized coatings. The normal size of inter metallic particles dipped in a bath < 15 µm. Such small particles are often found buried in the coating, patches of oxide skin taken up mostly on the corner of the coated strip so are not visible and distinguishable. As a matter of fact, most defects occur because of a rough or mechanically damaged substrate surface, insufficient cleaning of the substrate, poor maintenance of bath and poor handling of bath.. Thus, galvanizers producing coated products must improve quality of the incoming steel strip, the batch equipment, the batch line heat treatment zone and the coating bath in order to meet the stringent quality requirements for exposed automotive body panel applications. For batch producing both galvannealed as well as galvanized products, the additional challenges are to improve quality of chemistry of bath and to control galvannealing batch to batch from bottom-dross formation, develop a galvannealing to galvanizing formation procedure to clear up or minimize the disturbance deposit bottom dross.

"Analysis of defects in hot dip galvanizing in steel structures", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.6, Issue 5, page no.427-437, May-2019, Available :http://www.jetir.org/papers/JETIR1905K55.pdf

"Analysis of defects in hot dip galvanizing in steel structures", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.6, Issue 5, page no. pp427-437, May-2019, Available at : http://www.jetir.org/papers/JETIR1905K55.pdf