The development of steel pipe production technology began with the rise of the bicycle manufacturing industry, the development of oil in the early 19th century, the manufacture of ships, boilers and aircraft during the two World Wars, the manufacture of thermal power boilers after World War II, the development of the chemical industry and the drilling and transportation of oil and gas, etc., have strongly contributed to the development of the steel pipe industry in terms of variety, output and quality. Usually steel pipe according to the production method, divided into two types of seamless steel pipe and welded steel pipe, this SSAW pipe supplier mainly to introduce you to welded steel pipe..
Welded steel pipe is seamed steel pipe, the production of pipe billet (steel plate and strip) with a variety of forming methods bent and rolled into the required cross-sectional shape and size of the tube tube, and then different welding methods to weld the seam together and get the process of steel pipe. Compared with seamless steel pipe, welded pipe has the characteristics of high product accuracy, especially wall thickness accuracy, simple main equipment, small footprint, continuous operation in production, flexible production, and wide product range of units.
SSAW pipe, submerged arc welding (including submerged arc surfacing and electroslag surfacing, etc.) is an important welding method, and its inherent advantages of stable welding quality, high welding productivity, no arc and very little fume make it the main welding method in the fabrication of important steel structures such as pressure vessels, pipe section manufacturing, and box beam columns.
In recent years, although there have been many kinds of efficient, high-quality new welding methods, but the application area of submerged arc welding remains unaffected. From the point of view of the share of the weight of the molten metal of various fusion welding methods, submerged arc welding accounts for about 10%, and has not changed much over the years.
When the wire is determined (usually depending on the type of steel welded), the matching flux becomes the key material, which directly affects the mechanical properties of the weld metal (especially plasticity and low-temperature toughness), crack resistance, the incidence of welding defects and welding productivity. Wire and flux with a weight ratio of wire: flux = 1.1 to 1.6, depending on the type of welded joint, the type of flux used, welding specification parameters. Compared with molten flux, sintered flux dosage is more economical, about 20% less can be used.