Basic investigation for life assessment technology of modified 9Cr–1Mo steel

Okamura, H.; Ohtani, Ryuichi; Saito, Kiyoshi; Kimura, Kazushige; Ishii, Ryuichi; Fujiyama, Kazunari; Hongo, Shigetada; Iseki, Takashi; Uchida, Hiroshi

doi:10.1016/s0029-5493(99)00181-8

Cited by 53 publications

(28 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, since the components fabricated from modified 9Cr-1Mo steel are to be used for 30-40 years in service, it is important that this alloy exhibits good microstructural stability over very long periods of exposure to high temperature service conditions. The LCF behaviour of this steel has been reported earlier under normalized and tempered [1][2][3][4][5][6][7][8] and thermally aged conditions [9][10][11] in air environment. Prolonged ageing of the alloy at elevated temperatures prior to testing was found to reduce the LCF and creep-fatigue interaction lifetimes [9][10][11].…”

Section: Introductionmentioning

confidence: 86%

Effect of sodium environment on the low cycle fatigue properties of modified 9Cr–1Mo ferritic martensitic steel

Kannan

Sandhya

Ganesan

et al. 2009

Journal of Nuclear Materials

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 86%

Effect of sodium environment on the low cycle fatigue properties of modified 9Cr–1Mo ferritic martensitic steel

Kannan

Sandhya

Ganesan

et al. 2009

Journal of Nuclear Materials

View full text Add to dashboard Cite

“…Low cycle fatigue; P92 ferritic steel; cyclic softening; microstructure LCF behaviour of this steel has been extensively studied earlier under normalised and tempered [1][2][3][4][5][6][7][8] and thermally aged conditions [9][10][11]. Ageing resulted in the formation of Laves phase with associated reduction in the toughness and LCF lifetimes of the alloy [5,7].…”

Section: Introductionmentioning

confidence: 99%

High temperature low cycle fatigue behaviour of P92 tungsten added 9Cr steel

Kannan

Srinivasan

Valsan

et al. 2010

Trans Indian Inst Met

View full text Add to dashboard Cite

Modified 9Cr-1Mo steel is being used extensively as structural material for steam generator components of liquid metal cooled fast breeder reactor and fossil fired power plants. The selection of this material is primarily based on a good combination of mechanical properties, high thermal conductivity, low thermal expansion coefficient and good resistance to stress corrosion cracking in water-steam and sodium environment systems compared to austenitic stainless steels. A further improvement of the thermal efficiency of modern steam turbines can be achieved by increasing the steam operating temperature. It has been found that the substitution of W for Mo enhances the high temperature tensile strength, fracture toughness and creep strength. This had led to the development of P92 Steel.The components of the steam generators are often subjected to repeated thermal stresses as a result of temperature gradients that occur on heating and cooling during start-ups and shut-downs or during temperature transients. This leads to low cycle fatigue (LCF) damage in the component. However, the data on LCF properties of the W added 9Cr steel (designated as P92 steel) is scarce and this paper aims in understanding the high temperature low cycle fatigue behaviour of P92 Steel.Total axial strain controlled low cycle fatigue tests have been conducted in air in the temperature range 823 and 873 K to ascertain the influence of temperature on the LCF behaviour of the steel. A constant ramp rate of 3 × 10 -3 s -1 was employed for all the tests. The alloy exhibited a continuous softening before the final load drop that occurred due to the propagation of macro fatigue cracks. The softening rate is more for the tests conducted at higher strain amplitudes compared to that of lower strain amplitudes. Fatigue life decreased with increasing temperature and strain amplitude. In this paper the observed LCF results have been explained based on the detailed metallography and fractography conducted on the failed samples.

show abstract

“…Further, since the components fabricated from Modified 9Cr-1Mo steel are to be used for 30-40 years in service, it is important that the material exhibits good microstructural stability over long periods of exposure to high temperature service conditions. LCF behavior of this steel has been reported earlier under normalized and Keywords: ferritic steel; low cycle fatigue; sodium environment; mod 9Cr-1Mo weld joints tempered [1][2][3][4][5][6][7][8] and thermally aged [9][10][11] conditions in air environment. Prolonged aging of the alloy at elevated temperatures prior to testing was found to reduce the LCF and creep-fatigue interaction lives.…”

Section: Introductionmentioning

confidence: 88%

Low cycle fatigue properties of modified 9Cr-1Mo ferritic martensitic steel weld joints in sodium environment

Sandhya

Kannan

Ganesan

et al. 2010

Trans Indian Inst Met

View full text Add to dashboard Cite

Mod.9Cr-1Mo ferritic-martensitic steel is the material chosen for the steam generator of the Prototype Fast Breeder Reactor being built at Kalpakkam, India. The use of sodium as a heat transfer medium for Liquid Metal Fast Breeder Reactors (LMFBRs) necessitates a comprehensive understanding of the effects of dynamic sodium on the Low Cycle Fatigue (LCF) behaviour of structural components. Moreover welds being the weak links in any structure, it is necessary to evaluate the LCF behaviour of joints in sodium environment, more so in Mod.9Cr-1Mo steel because of the well established Type -IV cracking in this material. With this aim in view, a programme has been initiated to evaluate the LCF properties of weld joints of this steel in dynamic sodium environment. A facility has been developed in-house for mechanical property evaluation in dynamic sodium. LCF tests conducted in flowing sodium environment at 823 and 873 K showed a similar trend in cyclic stress response in air and sodium environments exhibiting a continuous cyclic softening behaviour. The fatigue lives are significantly improved in sodium environment when compared to the data obtained under identical testing conditions in air environment. The lack of oxidation in sodium environment is considered to be responsible for the delayed crack initiation and consequent increase in fatigue life. Comparison with RCC-MR code shows that the design curve based on air tests is conservative.

show abstract

Basic investigation for life assessment technology of modified 9Cr–1Mo steel

Cited by 53 publications

References 3 publications

Effect of sodium environment on the low cycle fatigue properties of modified 9Cr–1Mo ferritic martensitic steel

Effect of sodium environment on the low cycle fatigue properties of modified 9Cr–1Mo ferritic martensitic steel

High temperature low cycle fatigue behaviour of P92 tungsten added 9Cr steel

Low cycle fatigue properties of modified 9Cr-1Mo ferritic martensitic steel weld joints in sodium environment

Contact Info

Product

Resources

About