1Cr5Mo is a medium alloy heat-resistant steel with good hydrogen corrosion resistance at high temperature.

In the atmospheric and vacuum distillation unit for processing high-sulfur crude oil, 1Cr5Mo alloy pipe is mainly used for high-temperature sulfur-containing oil and gas pipelines such as the bottom pipeline of atmospheric and vacuum distillation tower, the furnace tube of atmospheric and vacuum distillation furnace, and the high-speed section of atmospheric and vacuum oil transfer line.

In the catalytic cracking unit, 1Cr5Mo seamless steel pipe is mainly used for high-temperature sulfur-containing oil and gas pipelines such as high-temperature slurry, catalysts and refining pipelines.

In delayed coking unit, 1Cr5Mo seamless steel pipe is mainly used for high-temperature sulfur-containing oil and gas pipelines such as high-temperature feed pipeline at the bottom of coke tower, high-temperature oil and gas pipeline at the top of coke tower, coking heating furnace tube and fractionator bottom pipeline.

Second, the use temperature:

The suitable working media for 1Cr5Mo seamless steel pipe are water, steam, hydrogen and sulfur-containing oil products. If it is used for steam, its maximum working temperature is 650℃; When used in working media such as sulfur-containing oil products, it has good high-temperature sulfur corrosion resistance, and is often used under high-temperature sulfur corrosion conditions of 288~550℃.

III. Chemical Composition and Mechanical Properties (Mechanical Properties):

Four, metallographic structure:

The structure of 1Cr5Mo is generally ferrite+pearlite. However, if the heat treatment is improper, especially if the cooling rate is too fast, it is easy to produce martensite structure.

Verb (abbreviation of verb) about heat treatment

Heat treatment mode: The heat treatment mode of 1Cr5Mo alloy tube is generally annealing. Pipeline components are manufactured by normalizing and tempering.

Heat treatment technology

(1) Normalizing treatment. The hot furnace is heated to 970℃ at 300℃/h (the cold furnace is heated to 200℃/h), and the holding time is 2.5~4 min/mm, and then it is cooled to below 300℃.

(2) Tempering treatment. When the heating temperature reaches 680℃, keep the constant temperature at 2.5~4 min/mm, then turn off the power supply, cool it in the furnace to below 300℃ and then air-cool.

(3) annealing treatment. Heating at the rate of 200℃ per hour. After the temperature rises to 850℃, keep the temperature for 2.5~4 min/mm, and then take it out of the furnace for cooling.