高氮奥氏体不锈钢的氮化物析出及其对焊接性影响

Nitride precipitation kinetics in high nitrogen austenitic stainless steel and its effect on weldability

高氮奥氏体不锈钢是用氮代替合金元素镍以获得优异的力学性能和抗腐蚀性能的合金结构钢,氮以固溶状态存在是材料性能优越的前提条件。高的固溶氮使钢在热力学上处于不稳定状态,存在氮化物析出倾向并诱发其它硬脆相的形成,弱化了材料性能。焊接加工时热影响区氮化物析出是固溶氮的一种主要损失方式。对等温过程中氮化物析出动力学以及胞状析出行为进行阐述,为材料的开发研制以及热加工过程的控制提供参考。

High nitrogen austenitic stainless steel is a kind of alloyed structural steel substituted nitrogen for nickel showing good mechanical and corrosion resistant properties. Nitrogen in the solid-solution state is the prerequisite for the austenite stainless steel to have excellent properties. The steel is thermally unstable due to high content of nitrogen in solid solution and has a tendency for nitride precipitation that will induce the formation of other hard and brittle phases, resulting in the degradation of properties. Nitride precipitation is the primary type of nitrogen loss in the heated affected zone during welding process. The nitride precipitation kinetics and cellular precipitation behavior were illuminated, which can provide some reference on the research and development of steel and the regulation of heat treatment process.