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Reading 2
9 Read the text From the History of Welding and refer the statements
1-4 to each of the passages of the text A-D
1. Application of welding techniques is decreasing nowadays.
2. Welding originated from the attempts to shape metal into useful forms.
3. Resistance welding is one of the earliest types of joining metals.
4. Industrial development in the 1950-s expedited (ускорять) the advance of
welding technologies.
From the History of Welding
A Welding is a technique used for joining metallic parts usually through
the application of heat. This technique was discovered during efforts to
manipulate iron into useful shapes. Welded blades were developed in the first
millennium AD, the most famous being those produced by Arab armourers
at Damascus, Syria. The process of carburization of iron to produce hard
steel was known at this time, but the resultant steel was very brittle. The
welding technique - which involved interlayering relatively soft and tough
iron with high-carbon material, followed by hammer forging - produced a
strong, tough blade.
B In modern times the improvement in iron-making techniques,
especially the introduction of cast iron, restricted welding to the blacksmith
and the jeweler. Other joining techniques, such as fastening by bolts or
rivets, were widely applied to new products, from bridges and railway
engines to kitchen utensils.
C Modern fusion welding processes are an outgrowth of the need to
obtain a continuous joint on large steel plates. Riveting had been shown to
have disadvantages, especially for an enclosed container such as a boiler.
Gas welding, arc welding, and resistance welding all appeared at the end of
the 19th century. The first real attempt to adopt welding processes on a wide
scale was made during World War I. By 1916 the oxyacetylene process was
well developed, and the welding techniques employed then are still used. The
main improvements since then have been in equipment and safety. Arc
welding, using a consumable electrode, was also introduced in this period,
but the bare wires initially used produced brittle welds. A solution was found
by wrapping the bare wire with asbestos and an entwined aluminum wire.
The modern electrode, introduced in 1907, consists of a bare wire with a
complex coating of minerals and metals. Arc welding was not universally
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