In order to improve the hardness and anti-friction wear performance of the barrel

the finite element predictive model of the temperature field of the continuous semiconductor laser heating pipe line was established

and the effect of laser parameters on the temperature field of the pipe line was simulated. Combined with the simulation results

the mathematical relationship between the depth of the quenching layer and the peak temperature of the temperature field was calculated. The laser quenching test was carried out and the effect of laser power

laser diameter and laser scanning speed on the hardness and depth of the hardened layer was investigated. The microstructure change after quenching was observed by using optical microscope. The results showed that the average hardness after laser quenching was increased from 400HV to 710HV

which is increased by 43.66%

and the depth of the hard line of yin and yang lines was 1.22mm and 0.61mm

respectively. After quenching

the surface roughness of the yang line material increased from 0.548μm to 0.7005μm

and the surface roughness of the yin line material decreased from 4.424μm to 3.804μm

respectively

which is meeting the requirements of use. The microstructure transformation of the yin and yang lines after quenching was observed and analyzed using optical microscope

and the transformation rules after laser quenching was explored.