Abstract:The thermal compression experiment of GH984G18 alloy was carried out using thermal-mechanical testing machines Gleeble3800. Based on the stress-strain curves obtained from the experiments, the processing maps of the GH984G18 alloy were established according to the dynamic materials model (DMM), then the hot working process window of alloy was built, and the influence of temperature and strain on the dynamic recrystallization of the experimental alloy was also analyzed. The results show that when the strain is small(ε≤0.2), the optimum deformation temperature is in the temperature range of 1030-1090℃ and strain rate range of 0.01-0.18s-1; with the increase of strain(ε≥0.3), the optimum deformation temperature moves to the high temperature range of 1180-1200℃ and strain rate range of 0.056-0.25s-1; and at the strain rate of 1s-1, dynamic recrystallization does not occur and dynamic recovery dominates when the temperature is lower than 900℃; and partial dynamic recrystallization occurs at the temperature of 1000℃ and the strain of 30%; and then the complete dynamic recrystallization occurs at the temperature of 1000℃ and strain of 60%.
[1] EVANS N D,MAZIASZ P J,SWINDEMAN R W,et al.Microstructure and phase stability in INCONEL alloy 740 during creep[J].Scripta Materialia,2004,51(6):503-507.
[2] ROSLER J,GOTTING M,GENOVESE D D,et al.Wrought Ni-base superalloys for steam turbine applications beyond 700℃[J].Advanced Engineering Materials,2003,5(7):469-483.
[3] VISWANATHAN V,PURGERT R,RAWLS P.Coal-fired power materials[J].Advanced Materials&Processes,2008,166(8):47-49.
[4] TOKAIRIN T,DAHL K V,DANIELSEN H K,et al.Investigation on long-term creep rupture properties and microstructure stability of Fe-Ni based alloy Ni-23Cr-7W at 700℃[J].Materials Science and Engineering:A,2013,565:285-291.
[5] 郭建亭,杜秀魁.一种性能优异的过热器管材用高温合金GH2984[J].金属学报,2005,41(11):1221-1227.GUO J T,DU X K.A superheater tube superalloy GH2984 with excellent properties[J].Acta Metallurgica Sinica,2005,41(11):1221-1227.
[6] KRISHNA R,HAINSWORTH S V,GILL S P A,et al.Topologically close-packed μ phase precipitation in creep-exposed Inconel 617 alloy[J].Metallurgical and Materials Transactions A,2013,44(3):1419-1429.
[7] SHINGLEDECKER J P,EVANS N D,PHARR G M.Influences of composition and grain size on creep-rupture behavior of Inconel® alloy 740[J].Materials Science and Engineering:A,2013,578:277-286.
[8] SHINGLEDECKER J P,PHARR G M.Testing and analysis of full-scale creep-rupture experiments on Inconel alloy 740 cold-formed tubing[J].Journal of Materials Engineering and Performance,2013,22(2):454-462.
[9] 谭梅林,王常帅,郭永安,等.Ti/Al比对GH984G合金长期时效过程中γ'沉淀相粗化行为及拉伸性能的影响[J].金属学报,2014,50(10):1260-1268.TAN M L,WANG C S,GUO Y A,et,al.Influence of Ti/Al ratios on γ'coarsening behavior and tensile properties of GH984G alloy during long-term thermal exposure[J].Acta Metallurgica Sinica,2014,50(10):1260-1268.
[10] PRASAD Y V R K,GEGEL H L,DORAIVELU S M,et al.Modeling of dynamic material behavior in hot deformation:forging of Ti-6242[J].Metallurgical and Materials Transactions A,1984,15(10):1883-1892.
[11] 李润霞,张磊,刘兰吉,等.Al-17.5Si-4Cu-0.5Mg合金热变形行为及其加工图[J].航空材料学报,2015,35(1):25-32.LI R X,ZHANG L,LIU L J,et al.Hot deformation behavior and processing maps of Al-17.5Si-4Cu-0.5Mg alloys[J].Journal of Aeronautical Materials,2015,35(1):25-32.
[12] 俞秋景,张伟红,于连旭,等.铸态Inconel 625合金热加工图的建立及热变形机制分析[J].材料工程,2014,(1):30-34.YU Q J,ZHANG W H,YU L X,et al.Development of thermal processing map and analysis of hot deformation mechanism of cast alloy Inconel 625[J].Journal of Materials Engineering,2014,(1):30-34.
[13] 曾卫东,周义刚,周军,等.加工图理论研究进展[J].稀有金属材料与工程,2006,35(5):673-677.ZENG W D,ZHOU Y G,ZHOU J,et al.Recent development of processing map theory[J].Rare Metal Materials and Engineering,2006,35(5):673-677.
[14] BALASUBRAHMANYAM V V,PRASAD Y.Deformation behaviour of beta titanium alloy Ti-10V-4.5Fe-1.5Al in hot upset forging[J].Materials Science and Engineering:A,2002,336(1-2):150-158.
[15] SUN M Y,HAO L H,LI S J,et al.Modeling flow stress constitutive behavior of SA508-3 steel for nuclear reactor pressure vessels[J].Journal of Nuclear Materials,2011,418(1-3):269-280.