Although 304 stainless steel (304 SS) is widely used, inevitable damage and fracture during service lead to failure, necessitating emergency repairs. Traditional repair techniques rely on large stationary equipment and high-energy inputs, making them unsuitable for rapid, convenient on-site emergency repairs. This study proposes a novel approach: applying a paste made from an Al/Fe 2 O 3 thermite powder system with CaO as a functional additive to the crack site. Combined with resistance wire Joule heating ignition technology, this method achieves in-situ high-strength repair of 304 SS cracks. Research indicates that incorporating 14.4% CaO into the total system not only moderates the reaction process but also regulates reaction kinetics and microstructure. This effectively promotes strong metallurgical bonding and the formation of a dense repair joint (26.25% small-angle grain boundaries), achieving an average microhardness of 519.1 HV (approximately 2.7 times that of the base material) and with an average tensile strength of 417.7 MPa. By integrating a simplified field process with precise material design, this work achieves high-quality on-site repair of 304 SS components without the need for high-energy-consumption fixed equipment, providing an innovative and practical new solution for emergency field maintenance.
Yu et al. (Sat,) studied this question.