Improvement of Production Processes of Seamless Steel Pipes for Oil and Gas Production

The article discusses the features of improving the technological processes of electric smelting, out-of-furnace processing, continuous casting and heat treatment of steel pipe blanks used for oil and gas production. To this end, ways to improve steel processing processes in electric furnaces and non-furnaces were shown, processes for the production of continuous casting pipes with special properties for oil and gas production were studied, the design of an alloying-refining lance (LRF) was developed, refining processes by blowing magnesium-based powders were studied, heat treatment modes for continuously cast billets during pressure treatment of pipe billets have been developed. The conducted research created the basis for the development of measures to organize the production of high-quality pipes for oil and gas production in the conditions of Baku Steel Company LLC. It has been established that blowing liquid steel with inert gases (for example, argon) in an intermediate furnace or treating it with a special composition of synthetic slag, the use of LRF in an electric furnace, the correct setting of the cooling system on a continuous casting machine (CCM), the use of a vacuum system on a continuous caster, the process of refining steel by blowing Powders based on magnesium oxide instead of lime are considered more effective means of improving the quality of steel. Based on the application of these measures, low-carbon low-alloy steel 13HFA was developed and seamless pipes with a ferrite-pearlite structure were obtained from it using continuous casting technology. The strength characteristics of this steel after casting and heat treatment fully comply with the requirements of the European standard. After heat treatment (hardening and high-temperature tempering), the surface of the pipes becomes harder (troostite + sorbitol), and the core has a soft, i.e., viscous (perlite + sorbitol) structure. This “layered” structure allows the pipes to operate successfully in difficult oil and gas production conditions.