Developing of friction stir welding process of high nitrogen containing stainless steel

利用负荷控制搅拌摩擦焊机成功地实现了高含氮奥氏体不锈钢(HNS)钢板的对接焊接。为了评估最佳搅拌摩擦焊工艺条件的范围，采用了几种焊接参数。研制成功了全熔透无缺陷对接焊接头。搅拌区的维氏硬度高于母材。焊缝的屈服强度和抗拉强度均超过母材。研究了接头的力学性能与热输入的关系，即实验测得的最高热温度。用定向成像显微镜(OIM)分析了搅拌区的晶粒度和搅拌区中心的物相组成。

Butt welding of high nitrogen-containing austenitic stainless steels (HNS) plates was successfully performed using a load-controlled FSW machine. In order to assess the range of the optimum FSW conditions, several welding parameter were adopted. Full-penetrated and defect-free butt welded joints were successfully produced. The stir zone showed a higher Vickers hardness than the base metal. The yield strength and the tensile strength of the welds exceeded those of the base metal. The relationship of mechanical properties of joints and effect of heat input, experimentally acquired peak heat temperature, was examined. The grain size in the stir zone and the phase constituents in the stir zone center were analyzed by OIM (Orientation Imaging Microscopy).