On July 25, a research team led by Professor Shen Tongde from the Clean Nano-Energy Center of the State Key Laboratory of Metastable Materials Science and Technology at YSU published their research findings with domestic and foreign scientists in the online journal Matter (a sister journal to Cell) titled “Discovery of a novel low-cost medium-entropy stainless steel with exceptional mechanical behavior over a wide temperature range”. The journal has an impact factor of 17.3, and the DOI is 10.1016/j.matt.2024.06.041. The full text is available at: https://authors.elsevier.com/c/1jUX69Cyxd6rKM.
Conventional stainless steels often exhibit a strength-ductility dilemma and low high-temperature strength and creep resistance. Nickel-based superalloys are widely used due to their superior high-temperature strength and creep resistance, but their raw materials and production costs are relatively high. High-entropy alloys have been extensively studied in academia since their discovery, but limited practical applications have been developed as they are not cost-effective. To address these challenges, Professor Shen Tongde’s team developed a novel low-cost, FeCrNiTiAl medium-entropy stainless steel (MESS) by adding small amounts of alloying elements such as Ti and Al to the primary components of conventional stainless steel (Fe, Cr, Ni). This new iron-based stainless steel can be fabricated readily through conventional casting and thermomechanical treatment techniques, and strengthened by high-density coherent nanoprecipitates. It has excellent strength-ductility synergy over a wide temperature range and superior high-temperature strength and creep resistance to some expensive nickel-based superalloys (such as Haynes 282 and Inconel 740). This breakthrough overcomes the challenges of the strength-ductility dilemma of conventional stainless steels and the high cost of nickel-based superalloys, thereby promoting the industrial application of high-entropy alloys. This novel medium-entropy stainless steel offers exceptional cost-effectiveness and is expected to partially replace the widely used conventional stainless steels and nickel-based superalloys.
(A) Yield strength versus the product of the ultimate tensile strength of the MESS at room temperature compared with those of different stainless steels and iron-based superalloys.
(B) Variation of yield strength with testing temperature of the MESS compared with those of conventional stainless steels and iron-based superalloys.
(C) Creep strain versus time curves of the MESS at 750°C under different stresses.
(D) Creep rate versus stress curves of the MESS and some other conventional nickel-based superalloys and heat-resistant steels.
This research was jointly conducted by YSU, University of Hong Kong (HKU), University of Tennessee (UT), Oak Ridge National Laboratory, Quanzhou Qingyuan Innovation Laboratory, and University of Science and Technology Beijing (USTB). YSU is the first author affiliation of the paper. Doctoral student Wen Kangkang (YSU), Cai Xuecheng (HKU) and Xin Shengwei (YSU) are co-first authors. Sun Baoru (YSU), Peter K. Liaw (UT) and Shen Tongde (YSU) are the corresponding authors. This research was funded by the National Natural Science Foundation of China and the Natural Science Foundation of Hebei Province.
