Evolution of Welding Technology
Discovery of metals is a boon to civilization. Man has meticulously learnt to extract metals from ores, purify and alloy it with other metals in order to shape basic objects, to suit his requirements. The primitive steps in this process were forging and soldering. Over years and especially during the last two centuries, welding technology has evolved in to a sophisticated science not only to join metallic parts, but also to reinforce them with strength, which can withstand tremendous operational stresses.
The need for Conservation
The wide spread use of metals in everyday life from household gadgets to industry and space craft has led to an increased demand for all types of metals like iron, steel, aluminum, cobalt, chromium, nickel and other alloys. The availability of these resources in natural form is depleting fast and consequently, the cost of raw materials is on a steep incline. Wear and tear of machinery, also results in crores of rupees worth of metallic parts ending up in scrap yards. Recycling i.e., making use of damaged or worn out parts by welding, has become a necessity and useful tool in the conservation of resources.
Importance of Reliability in Weld Treatment
As important as the need for conservation, so important is the reliability in reclaiming worn out metallic parts. Welding necessitates heat input which generates stress on the base metal being reclaimed. The stress could cause cracks, distortion, warping or even weakening of the metal, thus defeating the purpose and usefulness of the component. Hence, in maintenance welding, one has to take care to avoid detrimental effects of heat input.
The Company has developed products and processes which ensure very high reliability of weld parts reclaimed through:
1. Low heat input techniques (LH-Alloys)
2. Weld metals which provide better strength and resistance
3. Procedures and precautions which ensure reliability of welded parts
In addition, problems caused by impregnation and contamination of oil and grease, metal fatigue, inadequacy of Vee-groove due to positioning of parts etc., are taken care under this technique.
Procedures, Precautions and their Importance
Welding jobs undertaken using LH-Alloy products and processes, requisites specific procedures and precautions.
For instance, in the case of welding cast iron (which is considered difficult), the following need to be adopted.
1. Weld ability test to check whether or not the job is amenable to welding
2. Use of low current
3. Short arc gap
4. Short bead
5. Skip welding techniques
6. Hot peening
7. Keeping the job at “hand heat”.
All the above factors play important role in minimizing the ill effect of heat on the base metal.
Recycling of waste resources and maintenance programme
Parts that are lying in the scrap yard, maintenance workshops and those lying in inventory form substantial resources to any organisation. These can be reclaimed and reused using LH-Alloy techniques at a fraction of the original cost. It would reduce operational costs resulting in sizeable profits. Needless to add, spare parts inventory can be cut down by over fifty percent. Proper techniques such as ‘ABC’ and ‘VED’ analysis coupled with sound organizational status and functional responsibilities would go a long way to increase production and efficiency.