激光功率对19Cr双相不锈钢焊接接头组织及性能的影响

Effect of Laser Power on Microstructure and Properties of 19Cr Duplex Stainless Steel Welded Joint

针对具有TRIP效应19Cr经济型双相不锈钢,采用不同激光功率的激光自熔焊开展了焊接对比试验,并对焊缝的宏观形貌、微观组织、力学性能和腐蚀性能进行分析。分析结果显示,焊缝正面宏观外貌的平整度随着激光功率的升高先升高后降低,激光功率为1000 W、1050 W和1100 W时焊缝成形较好;在焊缝处奥氏体相含量相对于母材含量较少,奥氏体含量的变化随着激光功率的变化先减少再增加,激光功率为1000 W时,焊缝处奥氏体含量最少;激光功率为700 W、1000 W和1300 W时焊缝处的平均硬度值为220HV_(0.1),母材处的平均硬度值为370HV_(0.1);激光功率为500 W、1000 W和1300 W的焊接接头电化学测试中,1000 W的不锈钢焊接接头的自腐蚀电流密度最低,点蚀电位最高。研究表明,激光功率为1000 W焊接时,19Cr双相不锈钢焊缝成形性最好,焊缝处显微硬度最低,且具有较好的耐腐蚀性能。

For 19Cr economical duplex stainless steel with TRIP effect,comparative welding tests were carried out by laser self fusion welding with different laser powers,and the macro morphology,microstructure,mechanical properties and corrosion properties of the weld were analyzed.The results show that the flatness of the front macro appearance of the weld first increases and then decreases with the increase of laser power.When the laser power is 1000 W,1050 W and 1100 W,the weld formation is better.The content of austenite phase in the weld is less than that of the base metal,and the change of austenite content first decreases and then increases with the change of laser power.When the laser power is 1000 W,the austenite content in the weld is the least.When the laser power is 700 W,1000 W and 1300 W,the average hardness value at the weld is 220HV_(0.1),and the average hardness value at the base metal is 370HV_(0.1).In the electrochemical test of welded joints with laser power of 500 W,1000 W and 1300 W,the self corrosion current density of 1000 W stainless steel welded joints is the lowest and the pitting potential is the highest.The research shows that when the laser power is 1000 W,the weld formability of 19Cr duplex stainless steel is the best,the microhardness of the weld is the lowest,and it has good corrosion resistance.