Effect of Shop-Primer Coating on S235JR Steel on MAG Weldability

Abstract

In this study, S235JR structural steel samples in uncoated condition and coated (shop-primer) in different thicknesses were welded by MAG (Metal Active Gas) welding method, and the effects of these applications on the mechanical and microstructure properties of the material were investigated. In the experimental studies, the first specimen group were used without any sandblasting and coating application, the second group specimens were sandblasted at Sa 2 ½ degree, and 25 µm, 50 µm, and 75 µm coatings were applied to the specimens in the other group. Surface conditions and coating thicknesses were selected as the variable parameters. With the examination of the radiography films, it was observed that the surface conditions affected the welded joint. As a result of the study, it was observed that altered coating thicknesses caused defects in the welding zone. It was determined that the coating thickness partially affected the mechanical properties, and the highest hardness values occurred in the weld zone in all samples. Relatively low values were obtained in tensile, bending and Charpy impact tests performed on sample groups with 75 µm coating thickness. The results were verified by the surface fracture, SEM, and EDS studies.

İmalat Ön Astar Kaplamanın S235JR Çeli̇ği̇ni̇n MAG ve SAW Yöntemleriyle Kaynaklanabi̇lirliği Üzeri̇ndeki̇ Etki̇sinin Karşılaştırmalı Olarak İncelenmesi̇

“…In these fabrications, the use of weldable shop-primer coating significantly speeds up and simplifies the preparation of structural members for assembly and welding. The shop-primer coating serves additional practical objectives, such as safeguarding structural components throughout the steel material production phase and providing protection during storage prior to the application of the initial paint system [1,2]. Typically, a shop primer is advised to have a film thickness ranging from 20 to 25 µm, a recommendation that is based on smooth test panels.…”