Numerical simulation and correlation research of multi-track overlapping laser quenching process for 40Cr steel

Laser quenching has a short process cycle and high production efficiency, it plays an important role in automobile, ship, machinery manufacturing, other fields. The surface hardness of 40Cr steel laser parts is uneven by unreasonable set on the overlap zone. This will affect microstructure quenched layer, resulting cracking, corrosion during service, hazards that ultimately reduce reliability. Numerical simulations provide effective way to quantitatively reveal transient evolution multi-field coupling between temperature field, stress phase transition field quenching, which directly determines extent zone properties. layer profile predicted effectively determine secondary tempering softening solve bottleneck problem quenching. innovation this paper establish coupled numerical model multi-track process. temperature, hardening, distribution were numerically calculated, size under different overlapping rates was evaluated, revealing internal mechanism correlation multi-fields microstructure, tested infrared thermometer, Axio Vert A1 Zeiss microscope, Thermo ScientificTM Apreo scanning electron Q10M microhardness tester, verified effectiveness simulation. research can theoretical basis for optimizing parameters production.