ORIGINAL PAPER The Inhibitory Effect of Magnesium Sulfonate as a Fuel Additive on Hot Corrosion of Generating Tubes of Power Plant Boiler Mohamad Sadegh Amiri Kerahroodi 1 • Khosrow Rahmani 1 • Masoud Yousefi 1 Received: 24 February 2017 / Revised: 2 August 2017 Ó Springer Science+Business Media, LLC 2017 Abstract Changing the power plant boiler fuel from natural gas into fuel oil during the cold months of the year causes hot corrosion in generating tubes. Visual observations, thickness and thermocouple measurements and ash analysis proved the hot corrosion by displaying the sticky melted ash, thickness reduction, surface temperature of tubes at about 600 °C and existence of complex corrosive elements such as sodium and vanadium, respectively. Therefore, based on the experimental data from the power plant, laboratory studies were performed to survey the corro- sion inhibition effect of magnesium sulfonate as an easy to use fuel additive. A low carbon steel, 70 wt%Na 2 SO 4 –25 wt%V 2 O 5 –5 wt%NaCl and mineral part of mag- nesium sulfonate ash were used as the generating tube material, corrosive and additive ashes, respectively. Two groups of specimens were coated with two dif- ferent compounds of synthetic ashes, in which the first group was containing cor- rosive salts and the second was a calculated specific combination of mineral part of additive ash and corrosive salts. Specimens were exposed to high temperatures up to 120 h at 600 °C. Power plant observations, XRF, weight loss criteria, SEM and FESEM were used to study the hot corrosion, and results were compared with similar studies. It was concluded that magnesium sulfonate could not attribute to reduce the emission of sulphurous gases. Although the first group of the specimens was highly suffered from corrosion, the other group of samples was protected against hot corrosion and the weight loss was decreased considerably. Morphology and XRD picks of corrosion products were described, and it was also concluded that Na 4 V 2 O 7 and NaV 3 O 8 compounds which are molten at 600 °C were responsible for hot corrosion. The additive inhibited corrosion through formation of Na 3 VO 4 with & Mohamad Sadegh Amiri Kerahroodi sadeghamiri@aol.com 1 Energy and Mechanical Engineering Department, Abbaspour-Power and Water- College of Engineering, Shahid Beheshti University, P.O. Box. 16765-1719, Tehran, Iran 123 Oxid Met DOI 10.1007/s11085-017-9802-9