Fiver year work plan

1
Summary of the fatigue crack growth work carried
since 2008 on PFBR structural materials
SS 316LN P91 steel
Base and weld metal characterisation Base metal characterisation
Effect of nitrogen on FCG was characterised at room temperature and found that the 0.14 wt nitrogen content found to have better crack growth resistance under cyclic loading due to the slip planarity Effect of DSA on FCG has been examined . DSA exerts beneficial effects on the FCG properties and the mechanism was identified through determination of activation energy
FCG characterisation of as weld was carried out at different temperature and anomaly in thresholds was observed. This anomaly was removed by incorporating an appropriate effective crack tips stress intensity factor range which takes crack tip shielding effects in to account The effective crack tips stress intensity factor range was also used for base metal characterisation of P91. Similar type of anomaly was removed . Hence, this parameter appear to be an appropriate to predict the crack growth rate.
AET method employed to understand the insight of the crack growth behaviour Achievement Different sub-stages have been observed in the FCG curve when compared to conventional FCG curve in Collaboration with Dr. C.K. Mukhopadhyay, Head, NDED AET method employed to understand the insight of the crack growth behavior of P91 steel in Collaboration with Dr. C.K. Mukhopadhyay, Head, NDED.
2
Summary of the fatigue crack growth/fracture work
carried since 2008 on PFBR structural materials
SS 316LN SS 316LN P91 steel
Mixed mode test facility has been developed successfully and employed for FCG characterisation for SS 316LN base at different extent of mode mixity. Mixed mode test facility has been developed successfully and employed for FCG characterisation for SS 316LN base at different extent of mode mixity. Employed for FCG characterisation for P91 steel also
FOR AUSC FOR AUSC FOR AUSC
Materials in the form of tubes collected (SS304HCu and alloy 617) Materials in the form of tubes collected (SS304HCu and alloy 617) Materials in the form of tubes collected (SS304HCu and alloy 617)
Extraction of 1/4CT sample from tube and calibration for DCPD, validity criteria for fracture test was verified Extraction of 1/4CT sample from tube and calibration for DCPD, validity criteria for fracture test was verified Extraction of 1/4CT sample from tube and calibration for DCPD, validity criteria for fracture test was verified
Ageing for different durations (5000, 10000 and 20000 h ) were planned Ageing for different durations (5000, 10000 and 20000 h ) were planned Ageing for different durations (5000, 10000 and 20000 h ) were planned
Limited FCG and Fracture tests have been carried out as follows. Limited FCG and Fracture tests have been carried out as follows. Limited FCG and Fracture tests have been carried out as follows.
SS304Hcu for (NFC and IMP) Alloy 617 for (NFC and IMP) Alloy 617 for (NFC and IMP)
NFC found to have better FCG resistance than that of IMP is due to the twins At room temperature alloy 617 NFC found to have better fracture resistance At room temperature alloy 617 NFC found to have better fracture resistance
Variations in the both properties were observed with respective to the location of the samples from tube need to be further verified Variations in the both properties were observed with respective to the location of the samples from tube need to be further verified Variations in the both properties were observed with respective to the location of the samples from tube need to be further verified
3
VISION on INSITU Micro-scale fracture/FCG testing
and development
Sl. No Project Target
1 Study of Micro-mechanism of deformation, damage and fracture under monotonic and cyclic loading Designing architecture of microstructure for damage tolerance requires a detailed understanding of how an advancing crack interacts with the microstructure (sometimes modifies it locally such as deformation induced transformation, free volume change etc) at multiple length scales. It is possible with the enhancements in the capabilities of in situ scanning and transmission electron microscopy (SEM and TEM)
Current status
1 Mechanical Stage for SEM has bee processed PO has been placed and item delivery date is in Nov 2017
2 Provision for carrying out the high temperature test Tensile, fracture and FCG
4
PFBR Project
FCG characterisation to be carried out
Sl No PFBR materials PFBR materials
1 Fatigue crack growth and fracture studies under mixed mode loading To develop appropriate predictive empirical crack growth model for mixed mode
2 P91 steel (BHAVINI ) base and weld metal characterisation Fabrication of sample completed, fracture test to be carried out
AUSC Project
Crack growth characterisation of various types
of AUSC materials under cyclic and monotonic
loading
Sl No Materials Materials
1 SS304HCu (NFC and IMP) Alloy 617 (NFC and IMP), IN 625
2 FCG properties at different temperature FCG properties at different temperature
3 Fracture properties Fracture properties
4 Effect of ageing on FCG properties Effect of ageing on FCG properties
5 Effect of ageing on Fracture properties Effect of ageing on Fracture properties
5
Purchase files status
Sl. No. Item description Cost, Lakhs Time Schedule Remark
1 Establishing metallographic facilities for fracture mechanics section (R Balakrishnan) 10.00 Jan 2017-Dec 2017 PO placed
2 Mechanical stage for understanding the deformation behaviour at microstructural scale 100.00 2012-17 PO placed
3 Fatigue crack growth testing machines (2 nos) 501.00 2012-2018 DAE appr
4 Crack measuring units (12 Nos) 270.00 2012-2018 DAE appr
5 Resonance based fatigue pre-cracker and fatigue crack growth testing (2 nos) 621.00 2017-2018 Tender stage
High temperature accessories for fracture and FCG testing High temperature accessories for fracture and FCG testing High temperature accessories for fracture and FCG testing High temperature accessories for fracture and FCG testing High temperature accessories for fracture and FCG testing
1 High temperature COD gages 14.00 2016-2017 completed
2 DCPD unit 17.00 2016-2017 PO placed
3 High temperature Capacitance gages (Smt . G Shanthi) 22.00 2016-2017 PO stage
4 Daily basis consumable requirements are maintained by Syed Meer Khaleem for FCG , fracture studies and SEM etc. Temporary advance