Tig Welding Steel
Tig Welding Steel
Weld science is an extremely profound subject and the art of welding is truly owned by highly skilled professionals. TIG welding is one of the very common techniques of welding in which a non-consumable tungsten electrode with a filler metal is used.
During practice, a question very often asked is that if TIG welding of carbon steel with 309 grade is apt or not, as apparently many welders have commenced consuming it in the filler metal, however the question more appropriate here is why has 309 become so common that the code is many times neglected!
In order to comprehend the usage of grade 309 for welding carbon steel you must first comprehend why code constraints the consumptions of this grade in certain cases in which still many welders are found consuming it. 309 grade when welded in to carbon steel can be quite risky because the weld afterwards becomes inconsistent and this happening mostly during the process of solidification, a crack develops as the metal solidifies, this is also known as hot cracking. Then how is it so that many welders overlook this factor and have somehow been successful with the use of this grade!
The welding science states that the art of welding is governed by true welders who truly know their skill by experience and quality learning. During the welding of carbon steels many times it happens so that the exact required conditions for the conduction of welding are almost impossible to achieve because in most cases welds are to be done in very small places where even placing an equipment is tricky and having a clear sight and so a welder encounters problems among which the most challenging is to construct a contaminant free environment for welding, likewise in case of welding carbon steel without the consumption of 309 grade the similar problems are encountered; when the welder tries to fill the groove, the unwanted porosity appears due to exposure to atmospheric gas and moisture or at times contaminants trace in causing failure of the weld, for instance the increased percentage of carbon in metals can cause rapid failure due to excessive accruement of hardest and especially when weld is further subject to machining the failure is meant to be.
Therefore many welder very cautiously introduce the 309 grade to avoid such a failure and it has proved successful, but then how do they overlook the hot cracking failure resulted due to 309 grade!
A welder always knows how to overcome their problems, some welders prefer reducing heat while some prefer inclusion of greater percentage of base metal, whatsoever a successful welder does come to a solution. In fact on occasional experience the failure caused by use of 309 grade weld to carbon steel happens to be merely in cases when full penetration butt weld is done or in case of the highly restrained welds. But even if you are sure that your job of welding carbon steel with 309 grade would not cause failure of inconsistency you must still remain extremely cautious and follow every precaution possible.