Effects of Martempering Heat Treatment on Corrosion Rate in 1.5Ni Laterite Steel

Abstract

Laterite steel is commonly used for applications in the industrial worldwide. The behavior of this characteristics of laterite steel can be repaired in various ways, one of them by special heat treatment. This research aims to determine the value of corrosion rates, hardness, and transformation in microstructure that occur in laterite steel contain 1.564% Ni after heat treatment. Heat treatment carried out is austenizing at 950 -C and then quenching water; oil and normalizing in the air. And also tempering temperature variations 100°C, 200°C, and 300°C. Tests carried out were CMS 100 corrosion test which is 3.5% NaCl solution media, hardness testing with Vickers scale, and metallographic testing using an optical microscope. The results obtained showed that a microstructure transformation in 1.564% Ni laterite steel after HT consisted of martensite, ferrite, pearlite, residual austenite, and bainite. The lowest value of corrosion rate obtained in the sample normalizing 300°C tempering air and the highest in raw material. Whereas the highest hardness value was obtained 459.7 HV in the non-tempered water quenching sample.