CASE STUDY OF A CRACKED BOGIE FRAME

SRI. P. K. SRIVASTAV – SSE NC /mech. w/s, Gorakhpur.SRI. SRIRAM YADAV- TECH Gr-I SRI. LALMANI DUBEY- TECH Gr-I SRI. NIRANKAR NATH OJHA- H Gr-ISRI. BIND KUMAR- H Gr-I

TEAM MEMBERS

COACH NO-92206 WGSCN NE TRAIN NO.-12592 DN CRACK LOCATION- BOGIE SIDE FRAME DATE OF FAILURE- 29-10-2014 DRG NO-ICF DRG- T-0-3-601

CASE HISTORY OF CRACK BOGIE

COACH NO- 92206 NE TRAIN –12592 YESHWANTPUR- GORAKHPUR EXPRESS

CRACK LOCATION ON BOGIE SIDE FRAME

IMAGES OF CRACK LOCATION

Ø A transversely crack on the bottom flange from one end of the bogie frame at a distance of 1050 mm was found. The distance between them was 10 mm. The crack transversely spread over the web’s width.

Ø At the edge of bottom flange near the crack surface a welding defect (cavity) was found which was transversely upto 16 mm.

Ø There was Beach mark on the crack surface of bottom flange

Ø Whereas on the crack surface of web, there was Beach mark on 50% area and rest portion was crystalline.

VISUAL EXAMINATION

On the inner side of the bogie frame at the bottom flange edge, it indicates that the welding operation was done which was Crack Initiation Location.

MICRO EXAMINATION

As per CMT lab, Gkps Investigation Report: The top & bottom flange as well as web’s

chemical structure and metallic composition after examination was according to the Standards IS 2062:2006 : Gr-Fe410WC & WA.

The transversely fatigue manner failure of the component at the edge of bottom flange during service occurred due to the presence of the welding defect (cavity).

CONCLUSION

According to Data of Condemned Bogie from Coach Rehabilitation Workshop, Bhopal 267 bogies were condemned in 2005-2007 Maximum No. Of condemnation due to failure of

head- stock of bogie due to Corrosion, Patch Work, Crack was 52.51%

60 Cases of failure of side frame was 15.07% 117 Cases of transom failure was 29.39% 12 Cases of longitudinal members failure was 3.9%

RDSO RECOMMENDATION

ØOut of above the side frame and transom are the most critically stressed areas of the bogie frame whereas head stock and longitudinal members are non-critical members.

The frame should be examined for cracks and thickness of plate of different section of bogie frame measured.

Reduction in the thickness of plate due to corrosion etc. shall not be more than 1.5mm for critical section and 2mm for non-critical section of actual plate thickness.

If the thickness of critical section has reduced more than 1.5mm then the bogie is to be condemned and if its thickness reduction in non-critical section is more than 2mm (head stock, Longitudinal member) they have to be replaced.

Wherever cracks are found on the bogie frame , the procedure as laid down in M&C dte’s report no. MC-53 should be followed for repair of cracked bogie frame.

RDSO INSTRUCTIONS IN VIEW OF ABOVE CASES

This test is to be done for detecting surface and sub surface defects.

The whole weld HAZ and parent metal near to weld shall be tested by this method to ensure defect free weld. After testing traces of iron powder shall be cleaned properly to avoid corrosion.

Magnetic Particle Test

This test is to be done for detecting discontinuities open to the surface. After testing all the dye must be washed out.

Dye Penetrant Test

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