Effect of Solution Annealing Temperature on Liquation Cracking Susceptibility of Alloy 617M
Effect of Solution Annealing Temperature on Liquation Cracking Susceptibility of Alloy 617M
M. Divya(Materials Development and Technology Group, Indira Gandhi Centre for Atomic Research); C. Mahata(Metallurgical and Materials Engineering, IIT); K. G. Pradeep(Metallurgical and Materials Engineering, IIT); C. R. Das(Materials Development and Technology Group, Indira Gandhi Centre for Atomic Research;A CI of Homi Bhabha National Institute); M. Vasudevan(Materials Development and Technology Group, Indira Gandhi Centre for Atomic Research;A CI of Homi Bhabha National Institute)
30권 8호, 2215~2228쪽
초록
Improvement in liquation cracking susceptibility of Alloy 617M, a Ni base superalloy is observed on modification of solutionannealing conditions for the first time in the present investigation. Results suggest that the heat affected zone of the alloy in asreceived condition is more susceptible to liquation cracking than in modified solution annealed condition. A reduction in totalcrack length up to 62% is observed after modification of solution annealing condition. Discontinuous elemental segregation ingrain boundary, reduced precipitation and formation of low-energy serrated boundaries after solution annealing is observed. This decelerate complete wetting of grain boundaries in the heat affected zone during welding/thermal cycling, resulting inimproved resistance to liquation cracking in alloy 617M. Marginal decrease in strength is attributed to increased grain size ofmaterial, whereas increased ductility in solution annealed condition is attributed to, reduced elemental segregation at grainboundaries and increased number fraction of low energy special boundaries. In this study, influence of secondary precipitatesand segregation on liquation cracking in the alloy is brought out and elucidated using scanning electron microscopy andelectron back scattered diffraction techniques.
Abstract
Improvement in liquation cracking susceptibility of Alloy 617M, a Ni base superalloy is observed on modification of solutionannealing conditions for the first time in the present investigation. Results suggest that the heat affected zone of the alloy in asreceived condition is more susceptible to liquation cracking than in modified solution annealed condition. A reduction in totalcrack length up to 62% is observed after modification of solution annealing condition. Discontinuous elemental segregation ingrain boundary, reduced precipitation and formation of low-energy serrated boundaries after solution annealing is observed. This decelerate complete wetting of grain boundaries in the heat affected zone during welding/thermal cycling, resulting inimproved resistance to liquation cracking in alloy 617M. Marginal decrease in strength is attributed to increased grain size ofmaterial, whereas increased ductility in solution annealed condition is attributed to, reduced elemental segregation at grainboundaries and increased number fraction of low energy special boundaries. In this study, influence of secondary precipitatesand segregation on liquation cracking in the alloy is brought out and elucidated using scanning electron microscopy andelectron back scattered diffraction techniques.
- 발행기관:
- 대한금속·재료학회
- 분류:
- 재료공학