Tu Yuguo, Peng Wei, Chen Liujie, Xiao Xueshan
School of Materials Science and Engineering, Shanghai University, Shanghai 200444, China.
Jiangsu Shanyuan Group Co., Ltd., Taizhou 225722, China.
Materials (Basel). 2024 Dec 25;18(1):26. doi: 10.3390/ma18010026.
In this study, a novel Cu-bearing 304 stainless steel doped with 4.0 wt.% Cu (304-Cu SS) was developed, and the effects of nitrogen microalloying (304N-Cu SS) and heat treatment on mechanical, antibacterial, and corrosion properties were investigated. It was found that when aging at 700 °C, the Vickers hardness and strength of the 304N-Cu SS first significantly increased with increasing aging time up to 4 h and then slowly decreased with further increase in aging time. The best combination of strength and ductility, namely, a yield strength of 319 MPa, ultimate tensile strength of 657 MPa, and elongation to fracture of 47.0%, was achieved in the 304N-Cu SS after aging at 700 °C for 6 h. Moreover, the antibacterial and corrosion rates of the newly developed 304N-Cu SS reached 99.67% and 0.0032 g·mh, surpassing those of 304-Cu SS by 0.38% and 9.4%, respectively. These enhancements in the mechanical, antibacterial, and corrosion properties were attributed to the precipitation of high-density nanoscale Cu-rich precipitates during aging. Our results demonstrate that nitrogen microalloying is an effective metallurgical method for the future development of new antibacterial austenitic stainless steels with simultaneously enhanced mechanical, antibacterial, and corrosion properties for direct drinking water distribution systems.
在本研究中，开发了一种新型的含4.0 wt.%铜的304不锈钢（304-Cu SS），并研究了氮微合金化（304N-Cu SS）和热处理对其力学性能、抗菌性能和耐腐蚀性能的影响。研究发现，在700℃时效时，304N-Cu SS的维氏硬度和强度在时效时间增加至4小时前随时效时间显著增加，之后随时效时间进一步增加而缓慢下降。304N-Cu SS在700℃时效6小时后，实现了强度和延展性的最佳组合，即屈服强度为319MPa、抗拉强度为657MPa、断裂伸长率为47.0%。此外，新开发的304N-Cu SS的抗菌率和腐蚀速率分别达到99.67%和0.0032 g·m²h，分别比304-Cu SS高出0.38%和9.4%。力学性能、抗菌性能和耐腐蚀性能的这些提升归因于时效过程中高密度纳米级富铜析出相的析出。我们的结果表明，氮微合金化是一种有效的冶金方法，可用于未来开发具有同时增强的力学性能、抗菌性能和耐腐蚀性能的新型抗菌奥氏体不锈钢，用于直接饮用水分配系统。
