Heterostructured antimicrobial stainless steel and method for synthesizing the same

A method for synthesizing a heterostructured antimicrobial stainless steel with improved yield strength and reduced strength-to-ductility trade-off, having a heterostructured lamella structure arrangement formed with lamellar coarse grains surrounded by ultrafine grains;

• and a plurality of defects activating multiple strengthening mechanisms including:
• interstitial solid solution alloying elements;
• substitutional solid solution alloying elements;
• twins;
• multiphasic interfaces formed with face-centered cubic austenite phase and body-centered cubic martensite phase;
• statistically stored dislocations;
• strain-induced phase transformation, geometrically necessary dislocations pile-ups;
• stacking faults;
• precipitates;
• high density of grain boundaries, and hetero-deformation induced strengthening,
• the method comprising:
• a) casting a starting alloy with addition of antimicrobial element;
• b) subjecting the starting alloy to solid solution treatment to form a solid solution;
• c) quenching the solid solution to form a solid-solution treated stainless steel;
• d) subjecting the solid-solution treated stainless steel to aging to form an aged stainless steel;
• e) subjecting the aged stainless steel to cold rolling to form a cold-rolled stainless steel;
• f) subjecting the cold-rolled stainless steel to a final heat treatment to form the heterostructured antimicrobial stainless steel.