Historical development of the history of metal welded connection can be traced back thousands of years ago, early in welding technology is the Bronze Age and Iron Age in Europe and the Middle East discovery. Arc welding and later developed carbon electrode arc welding have been widely used in industrial production.
In the early 20th century, the demand for military equipment in World War I and World War II was very high, and the corresponding cheap and reliable metal connection process was paid attention to, which promoted the development of welding technology.
However, as engineers continued to improve the metal coating technology (i.e., flux) on the electrode surface in the 20th century, the new electrode can provide a more stable arc and effectively isolate base metals and impurities, therefore, arc welding can gradually replace combustible Gas welding has become the most widely used industrial welding technology.
Art creation and craftsmanship are always inseparable. The emergence of welding as an industrial technology meets the needs of metal art for the development of new processes. On the other hand, the unique and wonderful changes produced by metal under the influence of welding heat also meet the needs of metal art for a new artistic expression language. In today's metal art creation, welding is expressed as a unique language of artistic expression. The art of metal welding can be separated from the traditional metal art as a relatively independent art form, because welding is art.
Precautions for welding arc length The length of the arc is related to the type of electrode coating and the thickness of the coating. Short arc can prevent harmful gases such as O2 and N2 in the atmosphere from invading the weld metal. The welding speed is appropriate. The welding speed has a corresponding change under the conditions of electrode diameter, coating type, welding current, heat capacity of the object to be welded, structure, standard, etc , Cannot be specified.
Selection of welding wire The selection of welding wire should be based on the type of welding steel , the quality requirements of welding parts, welding conditions (thickness, groove shape, welding position, welding conditions, post-weld heat treatment and welding operations, etc.) and cost. The order of selecting conductors for consideration is as follows: 1. Welding wires are selected according to the steel types of carbon steel and low-alloy high-strength steel welding structures, and welding wires that meet mechanical properties are mainly selected according to the principle of "equal strength matching". For heat-resistant steel and weather-resistant steel, the main consideration is the similarity of the chemical composition of the weld metal and the base metal to meet the requirements of heat resistance and corrosion resistance. Welding process performance includes arc stability, size and number of spatter particles, slag removal, weld appearance and shape. For the welding of carbon steel and low alloy steel (especially semi-automatic welding), the welding method and welding material are mainly selected according to the welding process performance.