THAT 11-77. Rods tungsten. Specifications.
1. Technical requirements
1.1. Tungsten rods shall conform to the requirements of these technical conditions TU 11−77.
1.2. The chemical composition of the material depending on the grades of tungsten must meet the following requirements.
|Grade of tungsten||Tungsten content (including oxide of thorium), %, not less||Sum of impurities and additives, %, not more||The content of the oxide of thorium, %|
|VT-10||99,95||0,05||1.0 to 1.5|
|BT-50||Of 99.94||0,06||4.5 to 5.5|
|Diameter||Length, mm, not less||Delivery condition|
|Nominal, mm||Pred. deviation %|
|1,0−1,9 in 0.1||±2,0||1000||drawn|
|For 2.0−2.4 in 0.2||600||drawn|
|Of 2.6 to 4.8 in 0.2||600||forged|
- In agreement allowed supply drawn bar with a diameter of 3.0 mm.
- Supply each party is allowed 10% of bars with a length of at least 70% of the specified in table. 2.
- Bars brands VRN VA and having a diameter greater than 9.5 mm, brands W-7, W-30, W-50 with a diameter of 10.5 mm and grades W-30 and W-50 with a diameter less than 2 mm are made by agreement with the supplier.
1.5. Bars must be free of holes, cracks, delaminations, large burrs and strokes. Allowed small touches, burrs, traces of forging or straightening within tolerance on diameter, and a single large burrs on the rods brands BT-50 and VRN.
1.6. The ends should be trimmed evenly. Slight chipped.
1.7. Bars must be straight. Deflection shall not exceed 1% of the measured length of the rod. By agreement with consumer it is permitted to supply nepremennym drawn bar.