06Ni9DR steel plate: It is a boiler plate/vessel plate series, a European standard grade, a steel plate containing 9% Ni, in which "D" and "R" respectively refer to the low temperature pressure vessel.
Implementation standard: 06Ni9DR implements GB/T24510-2009 standard, 9% Ni steel plate for low temperature pressure vessels.
Flaw detection implementation standard: 06Ni9DR flaw detection implements JB/T4730.3-2005 standard, non-destructive testing of pressure equipment.
Ultrasonic testing: The 06Ni9DR steel plates should be ultrasonically tested one by one in accordance with JB/T4730.3, and the qualification level is Class I. According to the negotiation between the supplier and the buyer, it can also be carried out according to other testing standards, which are specified in the contract.
06Ni9DR cryogenic vessel plate delivery state: the steel plate is delivered in the quenching and tempering heat treatment state. In order to improve the toughness of the steel, intermediate heat treatment (twice quenching) can also be performed, and the steel plate with a thickness of not more than 12mm can also be tempered twice. Fire and tempering state delivery, the tempering temperature of the steel plate is not lower than 540℃.
Smelting method: The steel adopts electric furnace + out-of-furnace refining method. The steel should be vacuum treated and should be fine-grained killed steel.
Chemical composition of 06Ni9DR steel plate:
C content not more than 0.1; Mn content between 0.30-0.80; Si content not more than 0.35; P content not more than 0.010; S content not more than 0.004; Ni content between 8.5-10; Mo content not more than 0.10; V content not more than 0.01; Alt content not less than 0.020
In order to improve the properties of the steel, other microalloying elements can be added and the Cr+Cu+Mo in the steel should not exceed 0.50%
The effect of each alloying element:
C ——Carbide precipitation will cause pitting corrosion, generally controlled at <0.08%;
Mn—austenite phase stabilizing element to improve wear resistance and nitrogen solid capacity;
Si—contributes to high temperature oxidation resistance and acid corrosion resistance;
Ni—stabilizing element, reducing brittleness and improving mechanical properties, enhancing acid resistance.
Mechanical properties of 06Ni9DR: the yield strength is not less than 565; the tensile strength is between 680-820MPa; the transverse performance is not less than 100
06Ni9DR cryogenic vessel plate is mainly used for the construction of low-temperature LNG storage tanks.