氮对316L型不锈钢等离子弧焊接性能的影响

氮作为一种强奥氏体化元素,在不降低韧性的前提下可以提高材料强度和抗腐蚀性能。为了研究氮含量对316L型不锈钢焊接性能的影响,采用两种不同氮含量的316L型不锈钢进行不填丝穿孔等离子弧焊接。通过力学、抗晶间腐蚀等性能的对比,结合金相组织观察,可以看出奥氏体不锈钢中氮元素含量的增加能够提高焊接接头的抗拉强度,但却促进了热影响区晶粒的粗化,导致热影响区的低温冲击性能降低。

Influence of nitrogen on the plasma-arc welding joint properties of 316L stainless steel

Nitrogen is a strong austenitizing element.It can increase austenitic stainless steel’s strength and corrosion resistance based on the premise of not lowering ductility of the material.In order to study influence of nitrogen on the welding joint properties of 316L stainless steel,the authors used two types of 316L with different nitrogen contents for plasma-arc welding without filling materials.Through a comparison of mechanical properties and resistance to intercrystalline corrosion,and in combination with the observation of the metallurgical structure,a conclusion was drawn that adding more nitrogen into austenitic stainless steel can raise both the tensile strength of the welding joint and the coarsening of grains in the heat-affected zone,which can lead to a decrease in low-temperature impact property of the heat-affected zone.