Sigma phase(s)is harmful to the mechanical properties of 2205 duplex stainless steel,and its precipitation amount is mainly determined by aging treatment parameters.This article investigates the effect of aging treatment at different temperatures and different periods on 2205 duplex stainless steel.The precipitation behavior of sigma phase and its influence on mechanical properties were analyzed.The relationship between sigma phase content,material elongation and hardness,and recommendations for coiling temperature and cooling method in actual production were made.The results show that sigma phase precipitated at the δ/γ interface during the initial aging process,followed by continuous growth to form coral-like bright white phases.The sigma precipitation pattern of the phase conforms to the trend of isothermal transformation curve(TTT curve).Along with the increasing amount of sigma phase precipitation,which enhanced the tensile strength and hardness of the material,the elongation decreases and plasticity deteriorates.It is recommended to control the coiling temperature below 800℃and cool it quickly in actual production.
万方数据