Advice please

[GWIZ]

Originally Posted by Aireys

Advice required please guys

Retaining nuts on low carbon steel Truck Body’s are to be welded inside the chassis sub frame. The Truck body’s are to be made in batches of 2000 with 90 retaining nuts on each body.
Can someone state a suitable welding process for this application and the reasons for selecting this process? Can you please explain how energy for welding is generated, and describe how the weld pool is protected from atmospheric contamination.

Many thanks
Stuart

Welcome to the site.

I'm just a hobbyist when it comes to welding.
never heard the term Projection welds but maybe that is just me. the use of dimples are common.

Somewhere stud-welding comes to mind.


Spot welding counts on forcing current (amps) through a smaller surface area in order to generate enough heat to melt metal.
technically resistance.
the dimples decrease surface area and increases resistance, the reduced surface area will heat and melt metal when a high amount of current try,s to flow through a small conductor (under sized conductor).

thick material conducts electricity (technically more surface area) better, less resistance is not going to generate as high heat.
with "out" dimples thick material will require a larger power supply in order to heat.

I use the old term current (amps)
technically power in watts may be more up to date.
IIRC: there may be some high voltage spot welders in the thousand volt ranges but low amps. then they do the math convert power in watts.

[GWIZ]

(c) Explain how energy for welding is generated.

Maybe its me? or its getting late...............
The power company generates it with generators.
in less the welder has a generator that uses fuel of some type.

A welding power supply converts generated supplied energy for proper welding to take place.