Steel for oil refining boiler tube and process channel and manufacturing method thereof

Abstract

The invention discloses a steel for an oil-refining furnace pipe and a process pipe and a manufacturing method thereof. The steel comprises the following chemical elements in terms of weight percentage: 0.05 to 0.15 percent of C, 0.25 to 1.00 percent of Si, 0.30 to 0.60 percent of Mn, 8.0 to 10.00 percent of Cr, 0.90 to 1.10 percent of Mo, 0.005 to 0.040 percent of Al, less than or equal to 0.014percent of N, larger than or equal to 1 of Ca / S and the balance of Fe and inevitable impurities. The manufacturing method of the steel comprises the following steps: 1) smelting; 2) warming ingot andhot charging, evenly heating, continuous rolling, and annealing and peeling of tube blank; 3) heating; 4) punching and tube rolling; 5) heating again and heat preservation; 6) air cooling after rolling; 7) heating and heat preservation; and 8) heating again and annealing at constant temperature after heat preservation. The steel has stable mechanical performance at the normal temperature, good high-temperature transient performance, hydrogen corrosion resistance and high-temperature oxidation resistance.

Description

A kind of steel for furnace pipe and process pipe for oil refining and its manufacturing method technical field The invention relates to the field of metallurgy and iron and steel, and particularly belongs to a condition where the long-term working wall temperature is between 288-625°C, the short-term temperature is ≤795°C, the working pressure in the pipe is ≤10MPa, and the oil (gas) contains high-temperature sulfur, hydrogen and other corrosive media conditions. The following seamless steel tubes for tube furnace tubes or process pipes and their manufacturing methods. Background technique At present, domestic refineries mainly adopt the rules of mixing domestic crude oil and imported crude oil, and sulfur corrosion problems are often encountered in the refining process, especially in the process of processing Shengli crude oil and Middle East crude oil, pipelines and equipment leak due to sulfur corrosion The frequent occurrence of accidents is one of the important facto...

AI Technical Summary

Problems solved by technology

However, because the Cr content of T9 / P9 is about 9%, the molten steel has a high viscosity during smelting, and the oxide inclusions are not easy to float up and get rid of, and it is difficult to control the purity; the material itself has defects such as dislocations, grain boundaries, and inclusion interfaces. Under the environment of hydrogen medium, the hydrogen intruded into the steel may react with carbon to form methane bubbles, which gather near the grain boundary cavities and inclusions, forming high local stress, thereby inducing bubbling and deteriorating the material