ASTM A333Gr6/ASME SA333Gr6 Low temperature steel pipe
Grade: A333Gr.6 / SA333Gr.6
Standard: ASTM A333 / ASME SA333
steel pipe production process
The production process of steel pipes is implemented with reference to the technology system of 20G steel.
Steel pipe dimensional deviation and weight deviation
Outer diameter deviation: The outer diameter deviation of the steel pipe shall meet the requirements
Wall thickness deviation: -8% ~ + 12%.
Weight deviation: -3.5% ~ + 10%.
Fixed-length accuracy: according to user requirements.
Straightness: ≤1.5mm / m.
Delivery status and heat treatment process of steel pipe
The steel pipe is delivered in the normalized heat treated state.
The normalized heat treatment process of the finished product is: 900 ° C ~ 930 ° C for 5 ~ 15min, air cooling.
Mechanical properties of steel pipes
The tensile properties of steel pipes shall meet the requirements of ASTM A333Gr6.
For steel pipes with a nominal wall thickness ≤ 8mm, the tensile test specimen is a longitudinal strip test specimen with a width of 12.5mm and a gauge distance of 50mm. For steel pipes with a nominal wall thickness ≥8mm, a round specimen with a gauge distance of 4D can be used.
The crushing factor is 0.07.
Each batch of steel pipes with an outer diameter greater than 21.3mm shall be inspected for impact performance Akv.
Impact test temperature
When the thickness of the small-sized impact specimen reaches or exceeds 80% of the actual thickness of the steel pipe, the test temperature is -45 ° C.
When the thickness of the small-sized impact specimen is less than 80% of the actual thickness of the steel pipe, the specimen thickness should be as large as possible. The test temperature was -55 ° C.
Hardness test (only when required by the contract)
If the contract requires the hardness to be tested in accordance with the NACE MR-0175 standard, a test piece of approximately 20-30 mm in length shall be taken from each batch of steel pipes, and the hardness shall be less than 22HRc.