‘The fight between a sword and a shield’ is the simplest expression to describe the cutting of high-strength steel plate that is used for a rocket, airplane, ship, and car. In order to improve performance and economic feasibility, industrial sites require lighter and stronger steel plate and due to such demand, the blade for steel cutting has to be stronger. For this reason, the competition to produce the strongest and most ideal blade is quite fierce in the related global industry.

The three elements that decide the performance of a steel cutting blade are diamond-like hardness (high hardness), power that bears strong impact (high-impact toughness), and wear resistance that is not easily diminished. Since metal with high hardness is easily broken by impact, it is crucial to improve the hardness and impact toughness at the same time. The lifespan of a blade for steel cutting does not exceed 3.5 days in the industrial sites.

In line with this, the research team of Professor Gwon, Hoon (Advanced Materials Engineering of Kookmin University) designed and produced an entirely new alloy and as a result, a blade with the same hardness as existing steel cutting blade and double impact toughness was developed. By using this blade, the lifespan of a blade used in the industrial sites can be doubled up to 7 days. It must be good news in the steel industry since the process of steel plate production has to be stopped whenever replacing the blade.

The development of a high-strength blade starts from the course of alloy design. It is the process to increase hardness by synthesizing Fe with carbon compound and at that time, hardness as well as impact toughness is decided depending on the type of carbon compound to be synthesized. In this process, computer simulation is effectively utilized. Based on the data on various materials and their characteristics that are accumulated through previous studies, alloy is designed using a computer and simulation is conducted accordingly. Then, alloy is produced followed by post-processing like heat treatment.
A team researcher Park, Seong-su explained, “Materials are combined in consideration of alloy synthesis process up to heat treatment.” Through such process, the research team was able to derive a material that was composed of iron, carbon, chrome, molybdenum, nickel, vanadium, silicon, manganese, and titanium with alloy grain (array of metal forming crystal) measuring less than 15 micrometers (㎛). Smaller alloy grain show better characteristics as desired. This material was verified to have outstanding hardness, impact toughness, and wear resistance compared to the commercialized blades in the industry.

In support of the Ministry of Science, ICT, and Future Planning for the research achievement and commercialization, the research team plans to commercialize it with Daewon Inmul Co., Ltd., an expert of this area. Going beyond the steel industry, it plans to expand the application area including cutting of high-strength tire cord and metal die for vehicle production while promoting overseas export.
Professor Gwon, Hun said, “Daewon Inmul just started its overseas promotion; however, it is possible to seize the world-leading technology by synthesizing this research outcome and its existing technical competence.”