Friday, June 27, 2014

The Process Of Stainless Steel Welding

By Sherry Gross


There are three classes of metals based in stainless steel; Austenitic, martensitic and ferritic. Classification is based on their crystal structure. Stainless steel has a chromium content of at least ten percent. Austenitic grades are available with lowered carbon content. The basic steps below act as a guide in stainless steel welding.

Ensure safety as an initial step. Always take precaution of others and yourself since gases and fumes generally affect health while electrocution can also be hazardous. Take note of the instructions provided by the manufacturer and provide the staff with safety gadgets. Make sure that ventilation is ensured by keeping exhaust at arc, put on protective gear for body, ears and eyes. Be alert not to come in contact with naked electrical wires.

Decide on the best joint design. This is important in ensuring strength of the welded steel. When joining the base metals, consider strength, thickness of the metal, bonding position and accessibility of the joint. There are five joints which are; lap, edge, butt, corner and t. The joints are arranged in various combinations to create varieties of welds. Use fixtures and jigs to help in securing work pieces. When joining, clamp the sheet metal, lap joints and fillet tightly.

There are many processes that you can choose from when working on the steel. One of them is the stick electrode which has an electric arc that is between metal base and metallic electrode that produces heat required in bonding. This process is both cheap though inefficient due to coating of slang and loss of stub. The tig process is easily performed on many metals. The arc that produces heat lies between the metallic base and the tungsten electrode and it is protected by inert gases. A filler metal may be added in case it is deemed necessary.

Welding of mig is faster on thin metal gauge and weighty plates. The process is provided with heat by the arc sandwiched by filler electrode and base metal. The gas doses the shielding. Mig welding come in two types; spray transfer and short circuit transfer. The short circuit is used in tiny gauges and produces shallow weld. The method of spray transfer continuously sprays metal droplets is undertaken to transfer the metal to the arc.

Supposing the method of your choice need shielding gas, ensure that you have the best gas for use. The stick electrode requires no shielding gas. Use either helium alone or mix it with argon when working on thicker sections while helium is advisable for deep penetration.

When the metal pieces are the same, make use of a filler metal that has the same composition with the base metals so that the weld will have uniform properties. Consider the mechanical characteristics, probability of cracking and compatibility when choosing filler metal with different applications of the base metal.

When using the method of stick electrode, use either direct current or alternating current. The direct current takes a single direction in the flow of circuit and the polarity it uses is either straight or reverse. The advantage with it is that it works even in low current settings. It is advisable to use straight polarity direct current in tig bonding.




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