Exploring AWS Welding Handbook

1. WELD 6
NICKEL AND COBALT
ALLOYS
Physical and Mechanical Properties
Exploring AWS Welding Handbook
Vol 5 – Chapter 4

2. WELD 6
Nickel
FCC Structure
Alloying
Is Metallurgy
of Nickel is
similar to
Iron?
Cobalt
FCC & HCP Structure /
Metastable FCC in
Room Temp
FCC Forms
Stabilization &
Effect of certain
alloying elements
(Ni, Iron & Carbon)
Controversial
effects of certain
elements
(Like Cr, Mo,
Tungsten & Silicon)

3. WELD 6
Structure of Wrought cobalt
Alloy in Solution Annealed
condition!

4. WELD 6
How Alloy 188 (R30188) is
exempted from other cobalt
alloys?

5. WELD 6`

6. WELD 6`
Is Nickel is readily soluble with other elements?
Solubility of Co & Fe in Ni
With limits in solubility of Cr (35 to 45%) & Mo (20%)
Is addition of Alloying elements has any adverse effect?
Is response of Ni alloy is similar to stainless steel?

7. WELD 6`
Ni Alloy Crystalline
structure up to melting
point ?
Is grain size of
BM and WM
of Ni Alloy can
be refined?
Techniques for
grain size
reduction?
Is Weld ability of Co
– alloys is generally
good?
Yes
Or
No

8. WELD 6

9. WELD 6
Residual Elements and
Weldability of Nickel and
Cobalt Alloy??? LeadSulfur
Boron Zirconium
Bismuth
Phosphorous
Insolubility
Eutectic
Reactions
Hot
Cracking

10. WELD 6
Effect of Boron and
Zirconium
vs
High Temperature
vs
Weldability

11. WELD 6
Adverse Effects of Sulfur in
ductility
Ductility
Sulfur
Filler
Metals
Magnesium
Wrought
Product
Form

12. WELD 6
Loss of Magnesium
VS
SMAW Process?
Magnesium
& Niobium
Sulfur
Recovery
???
Magnesium

13. WELD 6
What happens if fusion
weld made without addition
of Filler metal in Ni, Ni-Cu
Alloys, Ni-Mo Alloys?

14. WELD 6
Titanium
Other Gas
stabilizing
elements
Prevent
Porosity?

15. WELD 6
Recommendation for
welding process
Mechanized
Automatic
welding process

16. WELD 6
Addition of filler metal and
weld quality???

17. WELD 6
Thank you
Next Presentation shall be about Ni & Co Alloys
Grouping….