Special Topic
2 . Improved mechanical properties : Overalloying the weld filler metal can also lead to improved mechanical properties of the weld joint . By increasing the concentration of nickel and other alloying elements , the weld can exhibit higher tensile strength , toughness , and resistance to deformation . This is particularly beneficial in structural applications where strength and durability are crucial .
3 . Matching or exceeding base metal properties : In some cases , the base metal used in a welding application may have higher alloying element content than the standard filler metal grade . In such situations , over-alloying the weld filler metal ensures that the weld joint matches or exceeds the properties of the base metal . This helps maintain consistency and integrity throughout the welded structure .
4 . Compensation for dilution : During the welding process , the base metal and filler metal mix together , leading to dilution of the alloying elements . Over-alloying the filler metal compensates for this dilution , ensuring that the resulting weld joint maintains the desired composition and properties .
It is worth noting that over-alloying the weld filler metal should be done with careful consideration of the specific welding application and the requirements of the final product . Balancing the alloying element concentrations is crucial to avoid potential issues such as hot cracking , reduced weld ductility , or increased sensitivity to intergranular corrosion .
It cannot be emphasized enough that following the correct procedure with the correct filler metals and shielding gas as described in the weld qualification is important . Further , operators need to train as if they were welding on the job , working with the exact base materials , filler metals , equipment and weld procedure specification ( asking your operators to train on anything less is like expecting an F1 driver to train on a truck ).
Operators have to develop welding techniques that produce successful results , practice them until they become second nature and then trust in those techniques in the field — which will be discussed in the next article !
About the Author
As part of the ESAB Specialty Alloys Group , Peter is technical support for stainless and nickel alloy filler metals . Peter is actively involved with TWI and is a non-executive director of The Welding Institute . Peter worked for Sandvik for 10 years and was Global Product Manager for Sandvik Welding up to 2018 , when ESAB purchased the filler metals business . Email : peter . stones @ esab . com .
Stainless Steel World Americas - June 2024 | www . ssw-americas . com 11