Being a welder you might have a question “How to make a good weld?”. Isn’t it?
Don’t worry. Here I have mentioned 4 things that you should remember to get a good weld.
To get a good weld, remember these 4 main things…
- Always have a good source of energy.
- You should remove the surface contaminants.
- Always protect the metal from atmospheric contamination.
- You should control the weld metallurgy (or weld properties)
Let me explain these points in short.
#1) Always have a good source of energy
- There are various types of welding processes used for metal joining operations.
- All these welding processes use the energy which is supplied in the form of heat.
- Depending upon the type of welding process, these heat supply can be in the form of flame, arc, electric current, or by mechanical means (like friction, explosion or ultrasonic vibrations).
- In very few welding process like fusion welding, the pressure is used to force the weld region to the plastic condition and then the metals are joined and fused together.
- Thus for all these welding processes, a source of energy is required.
- This source of energy should be good and as per requirements of the process.
- If there will be any issues in the source of energy, then ultimately the quality of welds will be affected.
#2) You should remove the surface contaminants
- In welding process, the surface contaminants include organic films, adsorbed gases, and chemical compounds of the base metal.
- When heat is used as an energy source for welding purposes, it removes the organic films and adsorbed gases.
- But the oxides films remains to be cleaned.
- The welding fluxes are used to clean the oxide films and other contaminants which are responsible to form a slag that floats and solidifies above the weld bead which ultimately protects the weld from further oxidation.
#3) Always protect the metal from atmospheric contamination
- In order to protect the weld pool and filler material from atmospheric contamination (specifically oxygen and nitrogen gas), some shielding gases are used.
- These shielding gases include helium gas, argon gas, or carbon dioxide gas.
#4) You should control the weld metallurgy (or weld properties)
- During the solidification of the weld, the microstructures are formed in the weld.
- The region which is affected by the heat will experience a much change in mechanical properties.
- Also for controlling the cooling rates of the weld, preheating and post welding heat treatment are used.
- Also during the manufacturing of the base metals, some alloying materials are added during the foundry process to control the properties of the weld metal.