Steel for deep sea oil extraction equipment and manufacturing method of steel forge piece for deep sea oil extraction equipment

Abstract

The invention discloses steel for deep sea oil extraction equipment and a manufacturing method of a steel forge piece for the deep sea oil extraction equipment. The manufacturing method comprises the steps that a special steel material is used as a blank, the surface of the blank is coated with a glass-like coating, the free forging and bound forging composite forging way is adopted for forging the blank, and a secondary forged blank is obtained; the secondary forged blank is normalized, the temperature is increased to 1150-1200 DEG C in a slow-fast-slow gradient heating mode, then quenching heat treatment is carried out in a water cooling-air cooling ternary cycle alternate mode, secondary tempering treatment in the tempering-water cooling-tempering-water cooing mode is carried out on the quenched secondary forged blank, and therefore the steel forge piece for the deep sea oil extraction equipment is obtained. Quenching cracking of large forge pieces in complex shapes is effectively prevented by combining the forging technology with the heat treatment technology, the comprehensive mechanical property, particularly the low-temperature toughness of the manufactured steel forge piece for the deep sea oil extraction equipment is greatly improved, and the manufactured steel forge piece can be well applicable to deep sea low-temperature working condition environment.

Description

technical field [0001] The invention relates to a steel for deep sea oil production equipment and a manufacturing method thereof, belonging to the field of metal forging and heat treatment. Background technique [0002] my country's oceans are rich in oil and gas resources, with proven reserves of tens of billions of tons, most of which are located in deep sea areas. However, because only the United States has mastered the manufacturing technology of the core equipment for underwater oil and gas field exploitation (underwater Christmas tree), my country has been forced to rely on imports from the United States for a long time, which is not only expensive, but also brings potential threats to my country's energy security, marine security and even coastal defense security. . [0003] The underwater oil production equipment is constructed by a series of production and control channels that are resistant to high temperature, high pressure, and high corrosion of crude oil (gas), ...

AI Technical Summary

Problems solved by technology

[0004] Usually, the size of deep-sea oil production equipment is large, and it is often difficult to forge through the materials processed by common forging processes. Some as-cast metallurgical defects, such as segregation, porosity, shrinkage cavities, etc. Greater stress concentration will be generated during the process, which often leads to cracking of forgings during heat treatment or during placement after heat treatment, or reduces the effective life of parts in service due to the existence of internal stress

In addition, because the environment of deep-sea oil production equipment is harsh working conditions in the deep sea, it has the characteristics of strong corrosion, low working temperature and high pressure. It is required that the materials of oil production equipment have good corrosion resistance and low-temperature mechanical properties. Manufacturing methods are often difficult to achieve, or the qualified rate of the produced materials is low, resulting in great waste

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