In order to study the effect of different tempering temperature on microstructure and properties of ( R4s) 22MnCrNiMo mooring chain steel flash weld zone. Cycle quenching ( water cooling) is preferred for quenching process. According to the actual production temperature and theoretical transformation point

the quenching temperature is 920 °C. The tempering temperature is 300

400

500

600 °C

and the tempering holding time is 30 min. The results show that with the increase of tempering temperature

the internal stress gradually decreases. When tempering at 600 °C

tempered sorbite structure is obtained in the weld zone

the tensile strength

yield strength

elongation and area reduction of the weld are 1 071 MPa

1 021 MPa

17% and 66. 60% respectively

at this time

the strength and toughness of the weld zone are best matched.