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Welders Home Welding FAQ

Welding Frequently Asked Question and Answers (FAQ)

Q. What is welding?

A. Welding is the joining of two or more materials through heat or high temperature and stress, forming a bond between them. This process is also known as welding.

Q. When and why should Alternatives to Welding be considered?


Whenever Welding is hard and costly and if there is no necessary need for the kind of metal continuity provided by welded joints. The most important point is that welding processes in common are associated with grand temperatures.

Q. A thin tube has to be welded to a thick plate or bar: why is it so difficultto do so?

A. The thick element absorbs a big quantity of temperature before reaching melting temperature. On the contrary the thin tube melts almost immediately. Therefore to weld correctly one has to alter the configuration of the joint so that the difference in thickness be kept to a minimum.

Q. How is a Crack repaired in a gray Cast Iron?

A. An extraordinary part addressing this question has been included in the WeldingAdvisers Site.

Q. Can an AISI 1141 cold drawn rod be welded to an ASTM A572 Gr.50 plate?

A. Fusion welding should not be attempted. AISI 1141 is resulfurized for increased free machining machinability. Sulfur causes hot smallness producing cracks. In certain cases it could however be resistance welded, if strengthrequirements are limited.

Q. How do I weld a splined end to a 4140 shaft hardened to 28-32 HRC?

A. Friction Welding are the best process would be

• It is fast and financial,

• its preparation is easy,

• it interests the entire section,

• it is in all probability would not need reheat treatment.

But some of the length is obsessive, and flash has to be removed. Concentricity may be a concern.

Q. How to judge of the adequacy of Spot Welds in Stainless Steel Sheets?

A. Austenitic Stainless Steel sheets are simply spot welded without any trouble. However, just byobserving how many general household equipment made of stainless steel fails sometimes in spot welds, one would think that it may be complicated to obtainadequate strength and to evaluate it.

Q. We are requested to weld with Low Hydrogen Electrodes. Why?

A. Hydrogen gas is gladly captivated because of its tall solubility in molten and hot steel, but it is discarded at lower temperatures as solubility decreases. Furthermore when dissociated in atomic form, hydrogen can disperse in the HeatAffected Zone


Q. Why is Fillet welding preferred for Rimmed Steel?

A. Rimmed Steel developed processes give a case or rim of very cleanmaterial free of defects. Conversely impurities tend to think in the center section of ingot or billet.

Q. How can tools made of nitrided tool steel be repair welded?

A. Nitrided layers should first be mechanically removed, for a deepness at least the two times of their unique nominal thickness.

Then welding can be attempted but its excellence may be doubtful because of diffused nitrogen.

Q. double-V-groove joint in a thick Pipe requires welding both from inside and from outside. Is there a preference as to which side to weld first?

A. The processes is used will most probably be either Submerged Arc Welding or Gas Arc Welding which are both providing tall weld deposition rate.

In order to guarantee the maximum quality the rootpass, however being done, has to be back gouged, that is ground for all its measurement lengthwise until sound metal is found. This grinding process with a transportable grinder can best be performed unhindered from the outside. Therefore the rootpass has to be laid down first from the in the interior of the pipe.

Q. What is Plasma Cutting?

A. Plasma cutting was invented as the effect of annoying to expand a well again welding process. several improvements then led to making this knowledge nowadays.

Plasma cutters provide the finest combination of accuracy, speed, and affordability for producing a variety of flat metal shapes. They can cut much better, quicker, and more routinely than oxy-acetylene torches.

Q. What kinds of materials can the machine cut?

A. Virtually any metal can be plasma cut including steel, stainless steel, aluminum, brass, copper, etc. Any thickness from 30 gauge through 1 inch can be cut, depending on the plasma cutter used.

The material used can be as large as 4ft wide by 20ft long. Plastics and wood are not electrically conductive and cannot be plasma cut. However, you can use a rotary saw, router, or other tool if you want to cut these materials in the Plasma MAX machine.

The accuracy of the machine is better than that of the plasma cutter. When the machine

Q. What Can I Use a Plasma Cutter for?

A. Plasma cutting is perfect for cutting steel, and non-ferrous fabric less than 1 inch thick. Oxyfuel cutting equipment requires that the worker carefully manage the cutting speed so as to preserve the oxidizing process.

Plasma is more merciful in this regard. Plasma cutting really shines in some niche applications, such as Plasma cutting extended metal, something that is almost impossible with oxyfuel. And, It is compared to mechanical mean of cutting, plasma cutting is typically much quicker, and can simply make non-linear cuts.

Q. What are the limitations to Plasma Cutting? Where is Oxyfuel preferred?

A. The plasma cutting machines are characteristically more costly than oxyacetylene, and also, oxyacetylene does not need access to electrical power or compressed air which may make it a more suitable method for some users. Oxyfuel can cut thicker section (>1 inch) of steel more speedily than plasma.

Q. How can tools made of nitrided tool steel be repair welded?

A. Nitrided layers should first be mechanically removed, for a deepness at least the two times of their unique nominal thickness.

Then welding can be attempted but its excellence may be doubtful because of diffused nitrogen.

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