P690QL1 weldable fine grain steel for pressure equipment

P690QL1 steel is a weldable fine-grain steel that is quenched and tempered. Executive standard: EN10028-6, number: 1.8881. P690QL1 is alloy steel, which belongs to steel for pressure equipment. It has good plasticity, toughness, cold bending performance and welding performance. The company can produce z15-z35 performance P690QL1 laminar tear resistance (thickness direction performance) steel plate.
 
P690QL1 weldable fine grain steel plates are widely used in petroleum, chemical, power plants, boilers and other industries to make reactors, heat exchangers, separators, spherical tanks, oil and gas tanks, liquefied gas tanks, nuclear reactor pressure shells, boiler drums , Liquefied petroleum gas cylinders, high-pressure water pipes of hydropower stations, turbine volutes and other equipment and components.
 

P690QL1 steel welding method

The submerged arc welding method of P690QL1 and Q370R dissimilar steel is characterized in that the method includes the following steps:
1) Submerged arc welding groove adopts asymmetric X-shaped groove, and the welding materials used are MCJQ-1 welding wire and SJ101 sintered flux;
2) Preheat P690QL1 and Q370R steel plates;
3) Submerged arc welding adopts DC reverse connection, current is 500-550A, voltage is 26-32V, welding speed is 35-1000px/min, line energy is 20-35kJ/cm, flux baking temperature is 350×2h;
4) Carry out hydrogen elimination heat treatment after welding;
5) After the welding seam has passed the non-destructive test, perform post-weld stress relief heat treatment at a constant temperature of 565 ± 20, and keep it for 2 hours. The submerged arc welding method of the present invention effectively solves the large difference in strength between the two kinds of dissimilar steels, and effectively guarantees the quality of the high-strength dissimilar steel welding joint.