Effectiveness of forced cooling during laser bending of duplex-2205

Abstract

Duplex-2205 is a dual-phase stainless steel having high mechanical strength and excellent corrosion resistance properties. Large spring back and high heat sensitivity are major problems in duplex-2205 during cold and hot working, respectively. Laser bending process is an advanced manufacturing process that is used for difficult to form materials with minimum heat-affected zone, negligible spring back, and high precision. Forced cooling (FC) has improved the efficiency during multiscan laser bending by reducing the waiting time. This study is focused on the analysis of the effectiveness of FC at the lower surface during single scan laser bending of duplex-2205 stainless steel. Worksheet geometry (thickness and width) and laser parameters (beam diameter, scanning speed and power) are varied to analyze the temperature profile, bend angle, mechanical and metallurgical properties during FC and compared with natural cooling condition. The results showed that a higher bend angle is observed in FC compared to natural cooling. Furthermore, tensile strength and hardness are improved whereas ductility is reduced due to change in phase distribution in the scanning region. Moreover, FC is found to be more effective at higher laser power, lower scanning speed, intermediate beam diameter, lower sheet thickness, and longer width of the worksheet.