Chromium 23 nickel 6 ferrite-austenitic stainless steel pipe and fabrication process thereof

Abstract

The invention relates to a Cr 23 Ni 6 ferrite-austenitic stainless steel which is manufactured from stainless steel materials containing components by weight percentage as follows: 22 percent to 24 percent of Cr, 5 percent to 7 percent of Ni, 3 percent to 4 percent of Mo, 0.15 percent to 0.25 percent of N, less than or equal to 0.03 percent of C and 1 percent to 2 percent of Mn, and the rest is Fe. The manufacturing technology of the Cr 23 Ni 6 ferrite-austenitic stainless steel of the invention is characterized in that: in hot piercing process, the hot piercing temperature is controlled to be 1150 DEG C to 1200 DEG C; the prior compression coefficient of a piercing plug is controlled to be 5 percent; the reduction of roller waist is controlled to be 12 percent and the ovality is controlled to be 1.08 to 1.11; in cold drawing / cold rolling process, cold deformation quantity is controlled to be below 50 percent; in heat treatment process, the solid solution temperature of products is controlled to be 1080 DEG C to 1100 DEG C and the solid solution temperature of finished products is controlled to be 1050 DEG C to 1100 DEG C. The Cr 23 Ni 6 ferrite-austenitic stainless steel has good chloride stress corrosion resistance, good pit corrosion resistance, high tensile strength and yield strength and good corrosion fatigue resistance and erosion corrosion resistance, and is widely used in the fields such as petroleum industry, chemical industry, natural gas industry and marine shipping and the like.

Description

technical field [0001] The invention relates to an alloy steel, in particular to a chromium 23 nickel 6 ferrite-austenite stainless steel pipe and a manufacturing process thereof. Background technique [0002] Stainless steel and its products, as a technical material and product, not only have good corrosion resistance, but also have good appearance and other characteristics. They are widely used in the national economy and people's daily life, and their application range is more Wider and wider. Commonly used stainless steel varieties mainly include 304 (0Cr19Ni9), 304L (00Cr19Ni9), 316 (0Cr18Ni14Mo2), 316L (00Cr18Ni14Mo2) and other steel types. [0003] There is an extremely thin chromium oxide film on the surface of commonly used stainless steel, which is called a passivation film. The film can prevent the metal from continuing to oxidize, so stainless steel has strong corrosion resistance. However, due to the inhomogeneity of defects, impurities and solutes in the sur...

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Problems solved by technology

For example, China discovered a world-class large gas field in the eastern part of Sichuan, but the natural gas contains a large amount of H 2 S, CO 2 , SO 2 , Cl 2 and other gases, the corrosion of steel is very serious, and there have been accidents where leakage due to corrosion of steel pipes has caused many deaths