Optimization of Zinc Coating Thickness by Unreplicated Factorial Design of Experiments in Hot-Dip Galvanization Process

• Published in: International journal of precision engineering and manufacturing 2022-10, Vol.23 (10), p.1173-1182
• Main Authors: Verma, Neha, Sharma, Vinay, Badar, M. Affan, Choubey, Niharika, Parihar, Rityuj Singh
• Format: Article
• Language: English
• Subjects: Business competition; Design of experiments; Engineering; Factorial design; Hot dip galvanizing; Immersion coating; Industrial and Production Engineering; Materials Science; Nickel; Optimization; Regular Paper; Silicon; Thickness; Zinc coatings
• ISSN: 2234-7593; 2005-4602
• DOI: 10.1007/s12541-022-00695-2

Over-coating of the zinc layer in the hot-dip galvanization process is a common issue. The coating thickness of zinc depends on various factors such as zinc bath temperature, dipping time, silicon percentage in steel, alloy composition in zinc bath, etc. In the current work, three factors: dipping time, silicon percentage in steel, and nickel percentage in zinc bath have been considered in an unreplicated 2 3 factorial design using secondary data from Bondareva (Materials Science Forum 992:689–694, 2020). Lenth’s method and normal probability plot are utilized to analyze the factorial design. It is identified that dipping time and nickel percentage are the two significant factors impacting the coating thickness. At 0.05% of nickel and 3 min of dipping time, minimum coating thickness is achieved, i.e., the thickness reduces up to 38.96% and 29.57% for 0.18% and 0.28% silicon-containing steels, respectively as compared to no nickel present in the zinc bath at 5 min of dipping time. All the experiments correspond to a bath temperature of 450 °C and phosphorus content of 2.5% in steels. The result is beneficial for industry to achieve better product quality and gain competitive advantage.