Creep properties, creep deformation behavior, and microstructural evolution of 9Cr-3W-3Co-1CuVNbB martensite ferritic steel

Abstract Creep deformation behavior and microstructure evolution of G115 steel were systematically investigated for temperatures of 625–675 °C under uniaxial tensile stress of 120–220 MPa. The relationship between minimum creep rate and applied stress followed the Bird–Mukherjee–Dorn (BMD) equation. The modified BMD equation was proposed using threshold stress to elucidate the actual creep deformation mechanism. The values of the threshold stress were determined to be 177.8, 91.4 and 87.6 MPa at 625, 650, and 675 °C, respectively. The true creep activation energy and the true stress exponent were 275.76 kJ/mol and 6, respectively. Thus, the dominant creep deformation mechanism was identified as dislocation climb. Three types of precipitates can be revealed after creep deformation: W-rich Laves, Nb-rich MX, and Cu-rich phases. The creep damage of G115 steel after creep deformation was characterized by martensite cracks and martensite fractures owing to the hardness and brittleness of the lath martensite structure. Further, a dense array of deep and equiaxed dimples appeared in the central region of fracture surfaces under the tested creep conditions. Ductile fracturing was the main fracture mechanism during creep deformation.

[1]  Kouichi Maruyama,et al.  Effect of precipitates on long-term creep deformation properties of P92 and P122 type advanced ferritic steels for USC power plants , 2009 .

[2]  Wei Li,et al.  The effect of microstructure evolution on the mechanical properties of martensite ferritic steel during long-term aging , 2017 .

[3]  M. D. Mathew,et al.  Effect of Laves phase on the creep rupture properties of P92 steel , 2016 .

[4]  M. Pham,et al.  Microscopic analysis of the influence of ratcheting on the evolution of dislocation structures observed in AISI 316L stainless steel during low cycle fatigue , 2013 .

[5]  H. Jing,et al.  Dislocation structure evolution in 304L stainless steel and weld joint during cyclic plastic deformation , 2017 .

[6]  G. Eggeler,et al.  On the nucleation of Laves phase particles during high-temperature exposure and creep of tempered martensite ferritic steels , 2014 .

[7]  Yingxin Zhao,et al.  High-temperature deformation and fracture mechanisms of an advanced heat resistant Fe-Cr-Ni alloy , 2017 .

[8]  Wei Liu,et al.  Effect of normalizing temperature on the strength of 9Cr–3W–3Co martensitic heat resistant steel , 2014 .

[9]  K. Guguloth,et al.  Uniaxial creep and stress relaxation behavior of modified 9Cr-1Mo steel , 2017 .

[10]  Jpm Johan Hoefnagels,et al.  Plasticity of lath martensite by sliding of substructure boundaries , 2016 .

[11]  H. Jing,et al.  Tensile mechanical properties, constitutive equations, and fracture mechanisms of a novel 9% chromium tempered martensitic steel at elevated temperatures , 2017 .

[12]  Wei Liu,et al.  Effect of microstructural evolution on high-temperature strength of 9Cr–3W–3Co martensitic heat resistant steel under different aging conditions , 2013 .

[13]  J. Narayan,et al.  Mechanical properties of copper/bronze laminates: Role of interfaces , 2016 .

[14]  F. Lu,et al.  Creep behavior and microstructure evaluation of welded joint in dissimilar modified 9Cr–1Mo steels , 2015 .

[15]  I. Charit,et al.  High temperature tensile deformation behavior of Grade 92 steel , 2014 .

[16]  Z. Xiang,et al.  On the physical models for predicting the long-term creep strengths and lifetimes of modified 9Cr-1Mo steel , 2017 .

[17]  S. Ravi,et al.  Creep deformation and fracture behaviour of modified 9Cr-1Mo steel in flowing liquid sodium environment , 2017 .

[18]  Zhengdong Liu,et al.  Toughness evolution of 9Cr–3W–3Co martensitic heat resistant steel during long time aging , 2016 .

[19]  J. Kysar,et al.  Geometrically necessary dislocation density measurements at a grain boundary due to wedge indentation into an aluminum bicrystal , 2017 .

[20]  M. Calcagnotto,et al.  Orientation gradients and geometrically necessary dislocations in ultrafine grained dual-phase steels studied by 2D and 3D EBSD , 2010 .

[21]  S. Leen,et al.  A physically-based creep damage model for effects of different precipitate types , 2017 .

[22]  X. Wu,et al.  Deformation-mechanism-based modeling of creep behavior of modified 9Cr-1Mo steel , 2017 .

[23]  K. Guguloth,et al.  Creep deformation behavior of 9Cr1MoVNb (ASME Grade 91) steel , 2017 .

[24]  A. Baltušnikas,et al.  Correlation between structural changes of M23C6 carbide and mechanical behaviour of P91 steel after thermal aging , 2017 .

[25]  C. Pandey,et al.  Effect of normalizing temperature on microstructural stability and mechanical properties of creep strength enhanced ferritic P91 steel , 2016 .

[26]  A. Fedoseeva,et al.  Creep behavior and microstructure of a 9Cr–3Co–3W martensitic steel , 2017, Journal of Materials Science.

[27]  B. Lim,et al.  Oxidation and fatigue crack propagation in the range of low stress intensity factor in relation to the microstructure in P122 Cr–Mo steel , 2009 .

[28]  Indrajit Charit,et al.  Creep rupture behavior of Grade 91 steel , 2013 .

[29]  Tomohiro Furukawa,et al.  Oxidation behaviour of P122 and a 9Cr–2W ODS steel at 550°C in oxygen-containing flowing lead–bismuth eutectic , 2010 .

[30]  S. P. Selvi,et al.  An assessment of creep deformation and rupture behaviour of 9Cr–1.8W–0.5Mo–VNb (ASME grade 92) steel , 2015 .

[31]  Kouichi Maruyama,et al.  Creep Behavior and Degradation of Subgrain Structures Pinned by Nanoscale Precipitates in Strength-Enhanced 5 to 12 Pct Cr Ferritic Steels , 2011 .

[32]  Z. Qiao,et al.  Martensite transformation kinetics in 9Cr–1.7W–0.4Mo–Co ferritic steel , 2014 .

[33]  M. Pham,et al.  Dynamic strain ageing of AISI 316L during cyclic loading at 300 °C: Mechanism, evolution, and its effects , 2012 .

[34]  F. Lu,et al.  Special zone in multi-layer and multi-pass welded metal and its role in the creep behavior of 9Cr1Mo welded joint , 2016 .

[35]  K. Nie,et al.  Hot deformation behavior and processing maps of fine-grained SiCp/AZ91 composite , 2015 .

[36]  Yuxing Tian,et al.  Study on the nucleation and growth of M23C6 carbides in a 10% Cr martensite ferritic steel after long-term aging , 2016 .

[37]  R. Hajra,et al.  Influence of tungsten on transformation characteristics in P92 ferritic–martensitic steel , 2016 .

[38]  Pradeep Kumar,et al.  Microstructure-based assessment of creep rupture behaviour of cast-forged P91 steel , 2017 .

[39]  Shuangbao Wang,et al.  New insight into high-temperature creep deformation and fracture of T92 steel involving precipitates, dislocations and nanovoids , 2017 .

[40]  Pradeep Kumar,et al.  Effect of normalization and tempering on microstructure and mechanical properties of V-groove and narrow-groove P91 pipe weldments , 2017 .

[41]  G. Eggeler,et al.  The nucleation of Mo-rich Laves phase particles adjacent to M23C6 micrograin boundary carbides in 12% Cr tempered martensite ferritic steels , 2015 .

[42]  Wei Liu,et al.  Effect of tempering temperature on the toughness of 9Cr–3W–3Co martensitic heat resistant steel , 2014 .

[43]  Hongyang Jing,et al.  Evaluating of creep property of distinct zones in P92 steel welded joint by small punch creep test , 2013 .

[44]  S. Zwaag,et al.  On the 650 °C thermostability of 9–12Cr heat resistant steels containing different precipitates , 2017 .

[45]  D. Smith,et al.  Influence of thermal ageing on the creep behaviour of a P92 martensitic steel , 2017 .

[46]  H. Jing,et al.  Analysis of creep crack growth behavior of P92 steel welded joint by experiment and numerical simulation , 2012 .

[47]  Hongshuang Di,et al.  Effect of martensite morphology and volume fraction on strain hardening and fracture behavior of martensite–ferrite dual phase steel , 2015 .

[48]  H. Jing,et al.  Quantifying the constraint effect induced by specimen geometry on creep crack growth behavior in P92 steel , 2015 .