Microstructure of Welded Joints of Steels based on the research work done by Dr. R. Narayanasamy, Retd. Professor (HAG), Dept. of Production Engineering, NIT Trichy

1. Microstructure of Welded Joints of Steels
Dr.R.Narayanasamy, B.E., M.Tech., M.Engg., Ph.D., (D.Sc.)
Retired Professor,
Department of Production Engineering,
National Institute of Technology,
Tiruchirappalli-620015, Tamil Nadu, India.

2. Figure of Welded Joint

4. HAZ in Weld Metal

5. Microstructure of the welded joint

6. Microstructure of steel joint (a) transverse cross section (b) weld metal (c) zone of
intersection of crystal growth directions; (d) segregation zone in the weld center; and
(e) fusion line zone

7. Appears
like
Dendrites
Microstructure of steel (weld metal)

8. Crystal growth in three different directions

9. Microstructure of segregation in steel

10. Fusion line zone

11. Filling welding of Gas Tungsten Arc Welding (GTAW)

12. Microstructure of heat affected zone (HAZ)

13. Region of overheated heat affected zone (HAZ) on the side of Arc
welding

14. Fusion
zone
Microstructure of Fusion zone in steel

15. Microstructure of heat affected zone (HAZ)
Ferrite
Carbide

16. Direction of crystal growth in steel weldment

17. TEM image of weld metal

18. Presence of acicular ferrite and upper bainite in weld metal

19. Acicular
Ferrite
Microstructure of weld metal in steel

20. Bainite Formation (BF) in steel

21. Formation of Acicular Ferrite (AF) & Bainite (BF) in steel

22. Ferrite formation in HSLA steel

23. Micrographs showing the presence of Widmanstatten ferrite

24. Widmannstätten ferrite (white) Widmannstätten cementite (white)
Widmannstätten structures of hypo and hyper eutectoid steel

25. The mechanism of acicular ferrite in weld deposits

26. High magnification micrographs from different locations in the build height. (a) The last layer,
top. (b) The middle of the build. (c) Bottom of the build. (d) Interface region between base
plate and beginning of the build.

27. Schematic diagram of acicular ferrite and bainite

28. Microstructure of Martensitic structure in steel weld metal

29. Weld microstructure without heat treatment

30. Microstructure of Advanced High Strength steel (AHSS)

31. Microstructure details of Stainless Steel

32. Structure of plate Martensite: (a) 1.2 %C steel, light micrograph; (b) Fe-
30%Ni alloy, light micrograph;

33. Weld decay in stainless Steel

34. Weld decay in Stainless steel

35. Weld decay in Stainless steel

36. (a) Untreated and (b) Treated with Nb or Ti

37. Intergranular corrosion

38. Weld metal in Duplex Stainless Steel

39. Causes and Prevention of Corrosion on Welded Joints

40. Thank
You