Large diameter welded pipe

Thick-walled straight seam welded pipes refer to steel pipes with a wall thickness of 8mm or more, which are commonly known as thick-walled straight seam welded pipes. These pipes have better pressure resistance than thin-walled ones and are generally suitable for high-temperature and high-pressure applications, as well as bridge load-bearing steel structures.

Thick-walled straight seam welded pipe control measures include: enhancing pre-production inspections of straight seam welded pipes and post-production casting billet quality; and improving the cleanliness of molten steel in thick-walled straight seam welded pipes through measures such as proper protective pouring.

① The thick-walled straight seam welded pipe manufacturer reduces the contact surface temperature between molten iron and carbon bricks to below 1150℃ through cooling, causing a thin iron skin layer to form on the carbon brick surface to isolate the molten iron from the carbon bricks. This not only forms an iron skin layer but also a slag layer for protection. This approach utilizes full carbon micro-porous, even ultra-micro-porous carbon bricks, and strives to enhance their thermal conductivity to lower the surface temperature to below 1150℃.

② Utilize ceramic bricks as lining to isolate the contact between ironwater and carbon bricks. As carbon bricks are difficult to resist ironwater erosion, a layer of ceramic bricks is artificially constructed on the surface of carbon bricks, forming the ceramic cup wall. The ceramic cup wall is useful only when the carbon bricks' resistance to ironwater erosion reaches the level of ceramic refractory materials. The welding process of thick-walled straight seam pipes begins at the exit of the heating furnace. After the pipe billet is scaled off by high-pressure water at the exit of the heating furnace, its front end is flash-welded with the tail end of the previous steel billet that has entered the rough rolling mill.