Influence of heat treatment on strength and toughness of laser cladding iron-based coatings.

Fe314 coatings were prepared on EA4T steel by laser cladding method, and were respectively subjected to 550 ℃ × 2 h Two kinds of heat treatment: annealing and annealing (1150℃×1h + 980℃×1h + 650℃×2h) after normalizing twice. The microstructure of the precipitated phase after heat treatment, the impact toughness and microhardness of the coating reveal the mechanism of heat treatment to improve the strength and toughness of the cladding layer. The results show that the Fe314 cladding layer had good plasticity and good room temperature strength after adopting the two-stage heat treatment process. The average microhardness was 228HV and the impact toughness was 64 J. The impact toughness of the cladding layer was related to the morphology and grain size of the precipitates. A large number of dimples can be observed on the impact fracture morphology, indicating that the fracture mechanism of the alloy was mainly ductile fracture. Comprehensive comparison, the comprehensive properties of strength and toughness were better at 1150℃×1h and 980℃×1h followed by 650℃×2h heat treatment. [ABSTRACT FROM AUTHOR]