高温合金熔化焊焊接性的研究进展

Research progress of weldability of superalloys by fusion welding

综述镍基高温合金和钴基高温合金熔化焊的研究现状,并阐述了焊接裂纹形成机理以及焊接工艺和合金成分对其焊接性的影响。镍基高温合金可以通过调整合金成分、析出相和晶界形貌、焊接工艺等来提高其焊接性。与沉淀强化型镍基高温合金相比,固溶强化钴基合金焊接性能良好,展现出良好的界面熔合性和较高的抗裂纹敏感性。新型沉淀强化钴基合金中γ/γ'点阵错配度为正值,推测γ'析出产生的压应力将降低焊接应变时效裂纹敏感性。沉淀强化钴基合金兼具优异的高温力学性能和可焊性,成为最具潜力的高温材料之一。

The research status of fusion welding of nickel-based superalloys and cobalt-based superalloys are reviewed.The mechanism of welding cracking and the effects of welding process and alloy compositions on weldability are described here.The weldability of nickel-based superalloys can be imp-roved by adjusting alloy compositions,changing the morphology of precipitations and grain boundaries,and choosing reasonable welding process parameters.Compared with the precipitation-strengthened nickel-based superalloys,the solid-solution strengthening cobalt-based alloys have good weldability and exhibit superior welding fusion interface and high cracks resistance.In recent years,researchers have found that the lattice mismatch ofγandγ'is positive in precipitation-strengthened cobalt-based superalloys,which would effectively reduce the sensitivity of welding strain aging cracks.The novel precipitation-strengthened cobalt-based superalloys have excellent mechanical properties and weldability,which are likely to become one of the most promising high-temperature materials.