Do you know ASTM b862 titanium? What is ASTM b862? Is it a standard?
What materials does this standard apply to? What is the standard content?
The answer is:
ASTM B862 is a standard for titanium welded pipes. If you want to know the details, please download the standard:
ASTM b862 Application of Titanium Welded Pipe
Titanium welded pipe has high strength, excellent plastic toughness and corrosion resistance, and is widely used in aerospace, shipbuilding and chemical plants.
What are the process requirements for ASTM b862 pipe welding?
In order to make better use of titanium pipes, we must master their weldability.
Titanium welding pipe welding material
Welding wire: TA2, ERTi-2; welding method: GTAW (manual tungsten arc welding)
Shielding gas: Use argon gas with a purity of 99.995% and a water content of not more than 50Mg%m3. Argon gas is used to protect the welding pool and the area of the inner and outer surfaces of the welding joint above 400℃.
ASTM b862 Preparation of titanium welded pipe before welding
1) Bevel processing
After the titanium welded pipe is cut, the groove is polished with an alumina grinder. Processing the groove does not allow the base material to overheat and discolor.
2) Cleaning of groove and welding wire
a. Clean the inner and outer surfaces of the bevel and both sides within 50mm, the cleaning procedure is as follows:
Grinding machine polishing → sanding wheel polishing → acetone cleaning
After cleaning, the welding operation cannot be directly carried out, and the end surface of the groove can be dried before operation. If it is left for more than 2 hours, you must clean it again or use self-adhesive tape and plastic cloth to protect the bevel.
b. The welding wire is also wiped clean with a sponge dipped in acetone and stored in a dedicated welding wire box.
c. The operator must wear clean gloves during the welding process.
ASTM b862 Titanium Welded Pipe Specification
1) Welding specifications
2) When welding, small wire energy welding should be selected within the range of qualified process parameters, generally controlled at 6~35KJ/cm, and small current and slow speed welding should be used.
3) The temperature between layers should not be higher than 200 ℃, to prevent the growth of crystal grains at high temperature for too long.
4) In order to protect the surface at the end of the arc after the arc is broken, the temperature of the welding point should be below 300 °C (the time is 15~60s, which can be gradually extended according to the pipe diameter from small to large) and then stop the gas supply protection.
5) Argon protection:
The specific protection measures are as follows:
a. For the welding of pipes with a DN greater than or equal to 450, the workers in the pipes put on gas masks and hold the protective cover to protect the back of the welding pool.
b. For the welding of pipes or fixed ports with a DN less than 450, the whole is filled with argon for protection. The inner surface of the pipe is 150-300mm away from the groove with a soluble paper seal, and then a ball of soluble paper is inserted to prevent the pressure in the pipe from being too high. The paper is destroyed, and then filled with argon to exhaust the air in the tube. Argon gas must be fully pre-filled before welding, and argon refill should be delayed after welding to fully cool the high temperature area and prevent surface oxidation.
6) The filler wire should be kept under the protection of argon during welding. After the arc is extinguished, the welding wire should not be exposed to the air immediately, and should be taken out when the welding seam leaves the protection. If the welding wire is contaminated or oxidized, the contaminated part should be removed.
7) No arc or test arc can be initiated on the surface of the weldment; the arc pit should be filled up when the arc is closed, and the interlayer joints of the multi-layer welding should be staggered from each other.
8) Under normal circumstances, each weld should be continuously welded once. If it is forced to be interrupted for any reason, it must be checked when re-welding, and it can be continued after it is confirmed that there is no crack.
9) If tungsten is caught accidentally during the welding operation, the welding operation should be suspended, the tungsten point should be cleaned with a polisher, and the end of the tungsten grade should be re-polished, and the welding operation can be re-executed after meeting the requirements.
The above-mentioned process points ensure that the welding of the titanium welded pipe is carried out normally, and also meet the welding quality requirements of the titanium pipe.
Specifications of titanium welded pipe that can be produced:
1. Outer diameter: φ38-2000mm
2. Wall thickness: δ2.0-16mm
3. Length: ≤6000mm