摘    要  2507 超级双相不锈钢的应用十分广泛。它具有耐点蚀、耐缝隙腐蚀的优异性能，还兼有强度高、抗疲劳强度高等优点。本研究对 2507 超级双相不锈钢采用激光焊，分析了离焦量、激光功率、焊接速度对焊接接头成型、焊缝两相组织比例和力学性能的影响。  离焦量、激光功率和焊接速度对 2507 超级双相不锈钢焊缝性能具有显著影响：离焦量为 0mm 时，焊缝的深宽比最高；离焦量为负时，焊缝的熔深熔宽值较大。保持离焦量和焊接速度一定时，随着激光功率的增大，焊缝的熔宽、熔深也随之增大。 对 2507 超级双相不锈钢进行激光焊焊接，选取适当的焊接参数和离焦量，得到相对理想的焊缝成形及接头性能。在离焦量为 0mm，激光功率为 2500W，焊接速度为20-25mm/s 的条件下，对板厚 5mm 的 SAF2507 进行激光焊接，可以得到均匀连续、成形良好的焊缝。 焊缝区的显微硬度要明显高于母材的显微硬度。在焊接过程中，由于焊缝区受到激光热输入的作用，焊缝中铁素体的含量增加，所以焊接接头的硬度高于母材的硬度。 激光功率和焊接速度对焊接接头的耐点蚀性能有显著影响。随着激光功率的增加，焊缝的耐点蚀性能不断提高；随着焊接速度的增加，焊缝的耐点蚀性能降低。 58961
毕业论文关键词：SAF2507；激光焊；离焦量；耐点蚀
Abstract 2507 super duplex stainless steel is widely used. It has the resistance to pitting corrosion, corrosion resistance of the performance is very good, at the same time it also has high strength, high fatigue strength. Laser welding of 2507 super duplex stainless steel was studied in this paper. The effects of the amount of out of focus, laser power and welding speed on the microstructure and mechanical properties of welding joint were analyzed. Away from the focus, laser power and welding speed has a significant effect on the 2507 super duplex stainless steel weld performance, keep the welding speed and laser power must, when the defocusing amount is positive, seam weld width and penetration depth is smaller; defocusing amount is negative, weld penetration weld width value is larger. Only change the laser power, with the increase of the laser power, the weld width and depth of the weld is also increased. The laser power is maintained at around 2500W, and the formation of the weld is better. When other conditions are certain, the welding speed increases, the weld width of  the weld is gradually reduced.. In the 2507 super duplex stainless steel laser welding, select the appropriate welding parameters and the amount of out of focus, can be the ideal weld forming and joint performance. Under the condition of 0, the laser power  is 2500W, the welding speed is 20 -25mm/s, the SAF2507 laser welding of thick 5mm can get the uniform and continuous, good shape and high hardness. The hardness of weld zone and heat affected zone is higher than that of base metal, because of the influence of heat affected zone and heat affected zone, the content of ferrite increases, and the hardness increases. The laser power and welding speed have significant influence on the pitting corrosion resistance of the welded joint. With the increase of laser power, the pitting corrosion resistance of the welded joint is increased, and the pitting corrosion resistance of the weld is also increased with the increase of the welding speed   
Keywords: SAF2507; laser welding; out of focus; pitting corrosion

目录

第一章绪论..1

1.1双相不锈钢的概述1

1.1.1双相不锈钢的耐腐性1

1.1.2双相不锈钢的焊接性3

1.1.3SAF2507的力学性能.3

1.2激光焊的概述..4

1.2.1激光焊接的特点和应用..4

1.2.2双相不锈钢激光焊研究进展.6

1.3选题意义及研究内容..7

1.3.1选题意义..7 2507超级双相不锈钢激光焊接技术:http://www.751com.cn/cailiao/lunwen_63985.html