冷金属过渡丝弧成形奥氏体不锈钢工艺特征研究

Study on process characteristics of cold metal transition wire arc forming austenitic stainless steel

采用冷金属过渡(CMT)焊接技术对奥氏体不锈钢进行了立体成形试验,重点研究了热输入对焊缝成形特征的影响规律。结果表明,随着热输入增大,单道焊缝熔宽明显增大,熔深略微增加,润湿角整体呈下降趋势。单壁墙堆焊层显微组织主要为枝状晶奥氏体和较多的骨架状δ铁素体。随堆焊层数增加,铁素体含量增加,而热输入较低时柱状枝晶细化,铁素体含量减少。随单壁墙层数的增加,低热输入下堆焊层硬度逐渐升高,大热输入下堆焊层硬度变化不明显。

The stereoscopic forming experiment of austenitic stainless steel was carried out by Cold Metal Transfer(CMT)welding technology.The effect of heat input on weld forming characteristics was studied emphatically.The results showed that the width of single weld increased obviously with the increase of heat input,and the depth of weld increased slightly,and the wetting angle decreased as a whole.The microstructure of the surfacing layer was mainly dendritic austenite and a lot of skeletonδferrite.The content of theδferrite increased with the number of surfacing layers,while the columnar dendrite was refined and the ferrite content decreased with the low heat input.With the increase of the number of layers of the single wall,the hardness of the surfacing layer increased gradually under the low heat input,while the hardness of the surfacing layer under the high heat input did not change obviously.