Since high carbon steel has high tensile strength and hardness and good wear resistance, and is cheaper than alloy steels, it has been widely used for manufacturing cutting tools, formers, springs, rails, etc. However, it is recommended to avoid welding of high carbon steel with poor weldability as much as possible because the weld zones of this steel can be easily cracked by high hardenability.
Nevertheless, there are many cases in practice that need inevitable welding. Especially, welding high carbon steel with good wear resistance and high impact strength such as 75Mn steel is one of the challenges in practice: butt-joint welding of track rails of 75Mn steel, for example.
Various welding methods were used to join high carbon steel such as rails, and in these methods, enough preheating and post-weld heat treatment were performed in order to prevent cracking. However, there may be cases where preheating or post-heating cannot be applied but should be avoided. If preheating and post-weld heat treatment of welding zones are not conducted, additional oxidation and deformation of weld zones can be prevented and welding costs can be saved.
Jon Yong Il, a researcher at the Faculty of Material Science and Technology, investigated an arc welding process for a long butt joint of high carbon 75Mn steel plates without preheating to ensure the quality of weld and high productivity.
The analysis of microstructures and mechanical properties of weld showed that the metal inert gas (MIG) welding process is a dominant one among various welding methods.
You can find the details in his paper “Application possibility of arc welding processes for long butt joint of 75Mn steel plates without preheating” in “The Journal of Engineering” (SCI).