Flange processing method

【Technical Field】

[0001] The present invention relates to a non-destructive testing method, in particular to a flange processing method.

【Background technique】

[0002] Wind power flanges are a component used professionally in wind power generation for connection between towers, generally ranging in diameter from 2 meters to 5 meters. Generally, wind towers are 65 meters, 70 meters, 85 meters, and more than one hundred meters high. In order to facilitate transportation, towers are generally manufactured and transported in three sections. It is divided into upper, middle and lower sections. In the manufacturing process, flanges are used for the connection of each section. The tower manufacturer welds the flange and the tower, and then transports them to the construction site in sections for assembly.

[0003] Technical characteristics of wind power flanges:

(1) Low-alloy high-strength structural steels Q345C, Q345E (S355NL used abroad) are generally used for flange materials. The carbon, sulfur, phosphorus and alloy contents are strictly controlled, and they have good toughness, welding performance, plastic forming performance and resistance Comprehensive performance such as corrosion performance.

[0004] (2) High requirements for forgings. The pressure vessel forging standard JB / T4726-2000 is adopted, and the flange nondestructive testing is 100% qualified.

[0005] (3) Mechanical processing and geometric tolerances are strict. Because the wind power tower is built in a relatively harsh environment, the height is generally more than 60m, and it is extremely inconvenient to install in sections, so the flange shape tolerance is very strict, and the technical standards such as hole center distance, coaxiality, flange flatness, etc. Control within 0.5mm.

[〇〇〇6] (4) The diameter of the wind power flange is too large. The matching size is in the range of 2000mm ~ 4800mm.

[0007] The flange in the prior art during the ring rolling step in the forming process is usually only cooled by cooling water, however, the surface of the blank is prone to scale, which cannot be removed.