In August 2024, Chinese steel mills launched a new series of nitrogen-containing martensitic stainless steel called THiE for the market. When applied to knife production, THiE exhibits high initial sharpness, edge retention, and corrosion resistance, making it a high-performance, economical martensitic stainless steel. The numbers 3, 4, and 5 in 3-chrome, 4-chrome, and 5-chrome steel refer to the carbon content in the stainless steel, which is 0.3%, 0.4%, and 0.5% respectively. Generally, lower carbon content results in softer steel, while higher carbon content produces harder steel. Comparatively, 3-chrome steel is less expensive, while 5-chrome steel is more costly.
Compared to the widely used 3 to 5-chrome stainless steel, THiE incorporates nitrogen, effectively replacing the role of carbon, molybdenum, and vanadium in steel materials. This addition enhances the steel’s hardness and corrosion resistance, achieving superior performance at a lower cost.
Chinese steel mills have gone through multiple stages, including technological breakthroughs in nitrogen-containing steel, pilot experiments, and production quality stability improvements. The research and application of nitrogen-containing steel have now reached maturity. THiE is a new product developed to meet the strong demand from enterprises for martensitic stainless steel with better performance, lower cost, and higher quality. The emergence of this new material provides knife and scissors manufacturers more opportunities to choose cost-effective steel materials.
Rapid “Reordering” by Enterprises: Lower Steel Costs with Better Product Performance
Notably, compared to the commonly used national standard 50Cr (chrome) steel, THiE steel can reduce costs by 20% while improving overall performance parameters by 10-20%. THiE steel has sufficient advantages in both price and performance, with costs expected to decrease further in the future.
After multiple comparative tests, it was found that 3-chrome products on the market have a hardness of 53-55, while products made with THiE all have high hardness, reaching 56-60, comparable to 5-chrome-15-molybdenum-vanadium products. This clearly demonstrates that THiE steel’s performance is on par with high-carbon performance steel grades. THiE steel can be applied not only to high-end kitchen knives but also to surgical scalpels and military knives.
While ensuring good material quality, Chinese steel mills are working on making THiE steel thinner to reduce enterprises’ grinding costs. Currently, they have achieved stable supply of 1.2mm thick strips and have developed 0.8mm thick strips for small fruit knife production, pending customer feedback before large-scale production.
Chinese steel mills are also developing 6-chrome nitrogen steel with higher hardness, suitable for cleaver production. They are committed to developing thinner steel materials to reduce enterprises’ subsequent rolling process costs. Weekly, laboratory specialists visit enterprises for regular exchanges, understanding application parameters, and striving to breakthrough industrial production technology to achieve higher production efficiency and more stable quality.