文档介绍：With the increase of the power, the pitting corrosion resistance of the welded joint increases firstly and then decreases, and keeps increase with the welding speed.
For 26Cr- super ferritic stainless steel, the precipitates in the base metal and the welded joint are mainly Ti and Nb carbonitrides, and no σ phase and χ phase found. Moreover, the welded joint owns less precipitates. Under the experimental condition, the tensile strength of the welded joint of 26Cr- super ferritic stainless steel is similar to the base metal (it changes within the range of 2% under various welding parameters), but the percentage elongation after fracture decreased by 20%. The fracture mode of the welded joint is the microporous gathered type, and the precipitation of Ti and Nb carbonitrides leaded to the decrease of toughness of the material. The pitting potential of the base metal is higher than that of the 30Cr-4Mo super ferritic stainless steel. And the Ti and Nb carbonitrides which were found at the bottom of the corrosion hole played the role of inducing the happening of pitting corrosion.
KEY WORDS:Laser welding, Super ferritic stainless steel, Microstructure, Mechanical property, Corrosion resistance property
目录
第一章绪论.......................................................................................................1
课题研究目的和意义...............................................................................1
铁素体不锈钢及其焊接性.......................................................................2
铁素体不锈钢的概述....................................................................2
超级铁素体不锈钢的发展............................................................2
超级铁素体不锈钢的焊接性........................................................3
激光焊接及其研究...................................................................................5
激光焊接特点................................................................................5
激光焊接的研究....................