NXF UNS N10276 2.4819/NiMo16Cr15W/C276 OD DN15-1200 Class 3000-9000 Nickel Alloy Forging Technology THD Straight or Reducing Tee

The forged threaded three-way fitting is a pipe diversion/concatenation connection component. It achieves pipe branching or merging through threaded connection, and can be tightly connected without welding, which is convenient for disassembly and maintenance. It is suitable for harsh working conditions such as high pressure and high temperature. The core advantage stems from the forging process: the material's molecular structure is dense, without any air pocket defects, and its pressure-bearing strength is much higher than that of cast products; the structure is compact and durable, and it is unlikely to deform or crack over a long period of use; the high-precision threads (RC/PT/ZG/NPT, etc.) ensure a secure connection and eliminate the risk of leakage.

The manufacturing process is "heating and forging for shaping → lathe processing of threads → heat treatment → accuracy inspection", which complies with domestic and international standards such as GB/T14626 and ASME B16.11. The specifications range from DN6 (1/4 inch) to DN100 (4 inches), with the mainstream being DN15-DN50. The materials can be carbon steel (for general industrial use), stainless steel (for corrosive environments), or alloy steel (for extreme working conditions with high temperature and pressure). It is widely applied in scenarios such as petrochemical industry, gas transportation, fire protection systems, building water supply and drainage, and mechanical equipment hydraulic/cooling systems.

1. Raw material pre-treatment

Select high-quality carbon steel (Q235/20#), stainless steel (304/316), or alloy steel (12CrMo/20CrMo) round bars/steel ingots. Cut them into blanks according to the target specifications. The blank size should reserve forging allowance (usually 10%-15% larger than the finished product) to ensure precise dimensions after forging.

2. Forging (Core Step)

Heating: Place the billet into a medium-frequency induction furnace or gas furnace and heat it to the forging temperature (for carbon steel, approximately 1150-1250°C; for stainless steel, approximately 1050-1150°C). The temperature is precisely controlled using a thermometer to avoid overheating or underheating.Forging: Use either free forging or die forging techniques. The heated billet is subjected to multiple stages of forging using a press or hydraulic press to gradually shape it into a three-way blank. During the forging process, the billet needs to be turned over multiple times to ensure uniform wall thickness (for the main pipe, branch pipe) in all parts, that the material fibers flow in the same direction as the force, and to eliminate internal pores and shrinkage defects, thereby enhancing the pressure-bearing performance.

3. Mechanical Processing (Thread and Dimension Refinement)

Coarse processing: Use a lathe to turn the interface part of the blank, removing the forging excess, and initially forming the interface contour to ensure the concentricity of the interface with the main pipe (tolerance ≤ 0.05mm).Fine thread machining: Use a CNC lathe in conjunction with high-precision thread cutting tools to perform thread machining on the interface, supporting standards such as RC (cylindrical pipe thread), PT (conical pipe thread), ZG (British taper thread), and NPT (American taper thread). The thread precision needs to reach the 6g/6h level to ensure the sealing performance of the connection.Dimension refinement: Fine-cut the inner and outer diameters and length of the main pipe and branch pipe to ensure that the dimensional tolerances comply with standards (such as outer diameter tolerance ±0.1mm, length tolerance ±0.5mm).

4. Heat Treatment (Performance Enhancement)

Based on the material and working conditions requirements, select the following heat treatment processes: Strain relief annealing: After low-temperature heating (for carbon steel, 500-600℃; for stainless steel, 800-850℃), slowly cool down to eliminate internal stresses generated during forging and processing, preventing deformation and cracking during subsequent use.Quenching + tempering: For alloy steel or products under high-pressure conditions, first quench (heating above the critical temperature, then quickly water-cooling or oil-cooling) to obtain a high-hardness structure, then temper (500-650℃) to eliminate brittleness and enhance fatigue resistance and toughness.

5. Quality Inspection and Packaging

Appearance inspection: Check for cracks, scratches, burrs on the surface, and whether the threads are complete and without misalignment.Dimension inspection: Use calipers, thread gauges, and three-coordinate measuring instruments to detect dimensional accuracy to ensure compliance with standards.Performance inspection: Conduct hydraulic tests (pressure at 1.5 times the working pressure, maintaining pressure for 30 minutes without leakage or deformation), and for some products, ultrasonic testing (to detect internal defects) is required.Packaging: Qualified products are coated with anti-rust oil or vacuum-packed, placed in wooden boxes or iron drums, labeled with specifications, materials, standards, etc., for easy transportation and storage.The entire process uses automated forging equipment and CNC processing technology, combined with a strict quality control system, to ensure that the products have high strength, high precision, and long service life, and are suitable for complex working conditions such as high pressure, high temperature, and corrosion.