Introduction to Welding

There is an urgent requirement of welding inspector base in Singapore for short term contract. One of the Connect Energy’s client in Singapore require inspector to support his activity in the Oil Gas Sector. Detail as below:

Responsibilities

• Responsible for Welding Inspection activity.
• Welding Inspector shall assist for developing new welding techniques, methods and procedures with the welders to enhance the productivity
• Ensuring that welding requirement, welder and welding activities are correctly specified and carried out in accordance to relevant codes, client specifications and contract standards. Read the rest of this entry »

Tungsten inert Gas (TIG) is frequently referred to as GTAW (Gas Tungsten Arc Welding). TIG welding is a commonly used for high quality welding process. TIG has become a popular choice of welding processes when high quality, precision welding is required.

In TIG process an arc is formed between a non consumable tungsten electrode and the metal being welded. Gas is fed through the torch to shield the electrode and molten weld pool. If filler wire is used, it is added to the weld pool separately.

TIG Welding Benefits

• Good quality welds
• Free of Spatter
• Welds can be made with or without filler metal
• Precise control of welding variables (heat)
• Low distortion

Shielding Gases

• Argon
• Mix Argon Hydrogen
• Mix Argon Helium

The purpose of Helium is generally added to increase heat input (increase welding speed or weld penetration). Hydrogen will result in cleaner looking welds and also increase heat input, however, Hydrogen may promote porosity or hydrogen cracking.

GTAW Welding Limitations

• Lower deposition rates.
• Requires greater welder dexterity than MIG or SMAW welding
• Costly compare with SMAW

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Welding is a process of joining material that commonly being used in most industry. Below a brief summary of welding history and its invention.

Early Ages of Welding
It was believed that the history of welding was started 2000 years ago. As examples in the Bronze Age, a small gold circular boxes were made by pressure welding lap joints together.

Egyptians and people in the eastern Mediterranean area learned to weld pieces of iron together during the Iron Age. Many tools were found which were made approximately 1000 before century. No certain record until the 19th century that welding, as we know it

today was invented.

Early 1800
The production of an arc between two carbon electrodes using a battery is credited to Sir Humphry Davy in 1800.

Edmund Davy of England is known with the invention of acetylene in 1836. In the mid-nineteenth century, the electric generator was invented and arc lighting became popular. During the late 1800s, gas welding and cutting was developed. Arc welding with the carbon arc and metal arc was developed and resistance welding became a practical

joining process.

1880-1900
Auguste De Meritens used the heat of arc for joining lead plates for storage batteries in the year 1881. It was his pupil, a Russian, Nikolai N. Benardos, working in the French laboratory, who was granted a patent for welding. He, with a fellow Russian, Stanislaus Olszewski, secured a British patent in 1885 and an American patent in 1887. The patents show an early electrode holder. This was the beginning of carbon arc welding. Bernardos’ efforts were restricted to carbon arc welding, although he was able to weld iron as well as lead. Carbon arc welding became popular during the late 1890s and early 1900s. Read the rest of this entry »