The addition of Ca element in steel such as S690QL properties can refine grain size, partly desulphurize and change the composition, quantity and morphology of non-metallic inclusions. It is similar to that of adding rare earth in steel. It can improve the corrosion resistance, wear resistance, high temperature and low temperature resistance of steel, improve the impact toughness, fatigue strength, plasticity and welding performance of the steel, and increase the cold heading, shock resistance, hardness and contact endurance strength of the steel.
The quality grade symbols of Q235 steel plate are A, B, C and D respectively. Different grades represent different impact temperatures. S690QL properties, Q235A is not required for impact toughness test; Q235B is required for impact toughness test at room temperature (20 ℃); Q235C is required for impact toughness test at 0 ℃; Q235D is required for impact toughness test at - 20 ℃. For the above-mentioned B, C and D grade steels, Akv ≥27J is required under different temperature requirements. At different impact temperature, the impact value is also different.
As we all know, steel pipes occupy more space in the process of transportation. If there is no good way of packing, the transportation cost for steel pipes will be a big expense. In view of this characteristic, our company is ingenious and adopts the nest package method to solve this problem perfectly. The premise of the nest package is that the diameters of the steel pipes are different, and the small diameter pipe is inserted in the large diameter pipe. This not only saves the volume, but also saves the transportation cost. It also reduces the loading and unloading workload by half, saves precious time, and enables customers to receive goods earlier.
Is there a difference between seamless steel pipe and ordinary steel pipe? The general requirements of S690QL properties ordinary steel pipe are not so high, which are used in ordinary buildings or structures. According to the different materials and standards, seamless steel pipe will have different application environment. For example, seamless steel pipe for boiler requires pressure value. Seamless steel pipe for petroleum cracking also has its own corresponding national standard. Seamless steel pipe can be divided into fluid pipe, gas cylinder pipe, boiler pipe, oil pipe, automobile steel pipe, ship pipe, structural pipe, etc.