Problems Seamless Pipe Suppliers Face Due to Improper Heating of Seamless Tubes

While it may seem to be an easy task, heat-treating pipes and tubes is crucial. Seamless pipe suppliers must be experts and experienced to conduct heat-treating correctly. If manufacturers fail to heat-treat pipes and tubes accurately, there are some problems that they will need to deal with. Let us find out some of the most common problems: 

  • Unqualified hardness is one of the most common problems manufacturers encounter while heat-treating seamless pipes. It means that the pipes are not hardened equally throughout their length. The defect may happen if pipe fabricators use an insufficient cooling rate during quenching. Unqualified hardness leads to the poor hardenability of the steel pipes, decarburization, retained austenite, and so on.  
  • Quenching is the heat treatment that changes the outer diameter of hot-rolled seamless pipes and tubes. The volume of the outer diameter of these pipes increases due to an increase in the diameter. In case the quenching heat treatment is insufficient, the outer diameter, bending degree, and ovality go out of tolerance.  
  • Uneven heating causes the pipes to bend instead of the pipes being straight. Tubing solution manufacturers must heat the pipes to a specific temperature (550°C) to straighten the curved outer and inner diameter. 
  • Another common issue that most pipe producers must deal with is steel pipe cracking. The problem takes place when engineers cool or heat the pipes too fast. The outer diameter cools down while the inner diameter is still warm, and vice versa. As a result, even stainless steel seamless pipes can develop cracks due to uncontrolled thermal distress.  
  • Sometimes, improper handling of the pipes may lead to scratches on the outer surface of the pipes. As you know, seamless pipes have smooth outer and inner surfaces. Hence, the hard injuries show on the surface prominently. The most common reasons for the problem are improper sliding of the pipes, faulty roller tables, and defective tools 
  • Overheating or burning is yet another issue that pipe producers encounter. Overheating causes the surface of the pipes to burn and causes the pipes to oxidize. Also, overheating can change the mechanical and structural composition of the raw materials. Overheating often leads to compromised structural integrity of hot-rolled seamless pipes 
  • If the heating furnace that the manufacturers use is not sealed correctly, air easily enters the furnace. As a result, the protective gas used during heat treatment oxidizes and weakens the pipes.  
  • Using an improper quenching medium can lead to cracks in the seamless tubes and pipes. Also, the pipe fabricators must save time moving from one step to another, such as tempering, quenching, annealing, etc.  

Heat treatment improves the structural and mechanical composition of steel pipes and tubes. There are two stages of heat treatment. Heat treating the pipes twice makes them stronger. It also improves their flexibility, eliminates their residual stress, removes stored gases, makes them wear-resistant, and so on. There are different processes that seamless pipe suppliers follow to heat-treat steel and alloy pipes, including quenching, tempering, annealing, normalizing, etc.  

Wrapping it up: 

Heat treatment is an unavoidable step in manufacturing seamless tubes and pipes. However, pipe producers must pay attention to the process so that they avoid making common mistakes. While some mistakes may seem inconsequential, they can compromise the integrity of the pipes.  

From choosing the correct quenching material to avoiding overheating, manufacturers must pay close attention to some minute details.  

Heat-treating seamless pipes and tubes is not only necessary but also an unavoidable step. Heat treating the tubes adds strength and durability, making them the ideal choice for many industries. Hence, most established seamless pipe suppliers have designated teams for heat-treating their products.