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Austenitic stainless steel tubes in the petroleum refining industry

Austenitic stainless steel tubes in the petroleum refining industry

Time:2022-03-18 Source:China Wuxi JiaNuo Special Steel Co.

Austenitic in the petroleum refining industry Submitted petroleum refining installation of representative equipment for atmospheric distillation installation, reduced pressure distillation installation, contact partition and reforming installation, hydrogenation desulfurization installation, hydrogenation synthesis installation. Most of the aggressive elements in petroleum refining are brought in together with crude oil, the primary ones being organic sulfur compounds (0.01-5% in crude oil) and inorganic salts (a few ppm-200 ppm). When heated, they synthesize, may consume H2S and hydrogen chloride and other active substances, in addition to crude oil also contains organic acids called naphthenic acid, the content of more will cause violent erosion of the material, in addition to crude oil into the erosion elements, in order to advance the results of the refining, in addition to water, hydrogen, but also the use of sulfuric acid, caustic soda, ammonia, etc. IMG_20210322_135033

The following problems exist in the use of stainless steel pipe in the oil refining installation at night.

(1) stress erosion fracture, through the crystal fracture (mainly chloride), intergranular stress erosion fracture (mainly sulfide).

(2) pitting erosion.

(3) intergranular erosion, the

(4) naphthenic acid mouth corrosion.

(5) carburization embrittlement.

Therefore, according to the oil refining installation of different erosion conditions choose different materials. Such as high-temperature sulfide system to consider Al and Cr sulfur erosion resistance and high-temperature strength, the use of Cr5-Mo above the material; high-temperature H2S-H2 system using 13Cr-Al, 18-8Ni steel; high-temperature high-pressure H2 system using Cr-Mo steel or overlay 18Cr-8Ni-Nb steel; low-temperature H2S-H2O system using 00Cr18Ni10. 00Cr17Ni14Mo2 or Monel stainless lining, H2S-HCl-H2O system using 00Cr18Ni5Mo3Si above the pitting resistance, stress erosion resistance stainless steel; naphthenic acid system, low flow rate conditions can be selected 00Cr17Ni14Mo2, high flow rate conditions need to be further studied; low temperature CO2 erosion system, usually at 200 ℃ or so can The use of 00Cr18Ni10; H2 installation in the reforming furnace reaction tube, high temperature steel pipe and all kinds of heating furnace bell hanger, bracket can choose 25Cr-20Ni, Incone stainless 800, etc.. Austenitic in the petroleum refining industry in the specific application cases: to petroleum refinery waste gas, natural gas or naphtha as raw materials, reversing a series of chemical reactions may produce ethylene, propylene, ethyl fast, etc., further synthesis may consume polyethylene, polystyrene, acetone, butadiene, etc.. About the synthesis of the process is similar to the chemical industry, will contact all kinds of acidic media, the decommissioning situation is quite harsh erosive, and the media premise changes overnight, the scale of the materials used is also wide, touching the stainless steel, iron-nickel-based corrosion-resistant stainless and nickel-based corrosion-resistant stainless.

(1) ethylene consumption ethylene consumption in the thermal synthesis furnace tube primary use of 0Cr25Ni20 or high carbon 25Cr-20Ni (HK40) centrifugal casting tube, is for high warmth and high creep fracture strength made by the choice. Incolog 800 stainless is used for the pipeline. In the low temperature premise using low temperature steel, only at -100 – 175 ℃ using 0Cr18Ni9.

(2) Acetylene Acetylene consumption, because the thermal synthesis temperature is above 1100 ℃, so the stainless trademark used is higher than the trademark used for ethylene consumption.

(3) Other processes Other processes include oxidation, hydration, dehydrogenation, dehydration, hydrocarbonization, anisotropy, etc. Will be in contact with the process-related acidic media, the primary materials used are 0Cr17Ni14Mo2 and 00Cr17Ni14Mo2, Inconel600, Incoloy800, No. 20 stainless and Hastelloy B, C, D, etc.. The working premise of these processes is shown in the following table. In the petrochemical process certain process links need to use sulfuric acid, hydrofluoric acid, phosphoric acid, hydrochloric acid and other aggressive media, according to the concentration of acid, temperature differences and the use of different corrosion-resistant materials.