Analysis of the entire process of forging flange production technology
As the core component of pipeline connections, the production process of forged flanges directly affects product quality and safety performance. This article is based on the NB/T47023-2012 and HG/T20615-2009 standards, combined with industry practice, to systematically analyze the four key production processes of forging flanges.
1, Whole forging and forming of steel billet
Steel billet forging is the core process of flange production, which refines metal grains and improves material mechanical properties through plastic deformation. The main processes include:
Heating control: The initial forging temperature is controlled at 1150 ℃± 50 ℃, and the final forging temperature is not lower than 850 ℃
Forging method: Large diameter flanges are forged using free forging (forging ratio ≥ 3:1), while small diameter flanges are forged using die forging (forging ratio ≥ 4:1)
Deformation process: including upsetting, stretching, punching and other processes to ensure that the material flow line is consistent with the direction of force
2, CNC lathe precision machining
The forged blank is processed by lathe to form the final size of the flange, and the key control points are:
Dimensional tolerance: The size of the mating surface should be controlled within ± 0.05mm
Surface treatment: The sealing surface roughness reaches Ra ≤ 3.2 μ m, which meets the requirements of NB/T47023-2012
Processing automation: using CNC lathes to achieve high-precision processing and improve production efficiency
3, Argon arc welding circumferential seam welding
The quality of argon arc welding circumferential seam welding directly affects the sealing performance of welded flanges:
Welding parameters: current controlled at 80-120A, argon flow rate of 8-12L/min
Weld quality: Weld excess height ≤ 1.6mm, 100% visual inspection is required
Post weld treatment: Perform stress relief annealing on the welded joint
4, Ultrasonic flaw detection
Non destructive testing is a crucial step in ensuring the quality of flanges
Testing standard: Complies with ASME V standard, with a detection sensitivity of ≥ 2mm equivalent defects
Testing ratio: Class 150 and above flanges require 100% testing
Defect handling: If excessive defects are found, they need to be repaired or scrapped
5, Industry standards and quality control
Material standard: Implement NB/T47008-2017 forging process specification
Inspection standard: Conduct size and performance inspection according to HG/T20615-2009
Quality control: Establish a full process quality traceability system from raw materials to finished products
Every step of the forging flange production process needs to be strictly controlled, and through standardized production processes and advanced testing methods, the reliable application of products in fields such as petrochemicals and pressure vessels is ensured. With the development of intelligent manufacturing technology, the production of forged flanges is gradually transitioning towards digitization and automation.
