Production method of 8630 super-long forge piece for deep sea Christmas tree equipment

Abstract

The invention discloses a production method of an 8630 super-long forge piece for deep sea Christmas tree equipment. The production method comprises the following steps: feeding, namely taking 8630# steel as a raw material steel ingot, wherein the steel ingot comprises the following chemical components: 0.3-0.33% of C, 0.15-0.35% of Si, 0.75-0.95% of Mn, less than or equal to 0.025% of P, less than or equal to 0.025% of S, 0.8-1.0% of Cr, 0.35-0.45% of Mo, 0.70-0.90% of Ni, 0.015-0.03% of Al, less than or equal to 0.35% of Cu, less than or equal to 0.06% of Nb, less than or equal to 0.06% of Ti, 0.03-0.06% of V, less than or equal to 0.0005% of B, less than or equal to 0.005% of Ca, less than or equal to 2 ppm of H, less than or equal to 20 ppm of O, less than or equal to 100 ppm of N, greater than or equal to 0.77% of CEV and the balance of Fe; carrying out forging; carrying out heat treatment; carrying out UT flaw detection; and carrying out machining.

Description

technical field [0001] The invention relates to a production method of an 8630 super-long forging for deep sea oil tree equipment. Background technique [0002] The underwater Christmas tree 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), that is, the Christmas tree body, tubing hanger, hydraulic control gate valve body, double-hole connector, pipeline It consists of main key components such as connectors and production jumper pipes. In view of the low temperature environment of the seabed, the temperature drop of the production medium, the external environmental load and the internal high pressure bearing working conditions, the key components of the subsea tree are not only required to have high strength, but also require good grain structure, low temperature toughness and heat resistance. Fatigue performance, that is to say, the base material of its key co...

AI Technical Summary

Problems solved by technology

[0003] However, there are various defects in the domestic 8630 forgings during the forging process, such as internal defects such as inclusions, looseness, micro-cracks, and coarse grains. These defects make forgings scrapped in flaw detection. The mechanical properties such as yield strength, tensile strength and impact toughness are greatly reduced, which eventually leads to early failure of forgings and low service life.

In addition, for the super-long 8630 forgings, there are also phenomena such as quenching cracks, surface decarburization and carbide segregation caused by improper control of forging process and heat treatment process.