Treatment Techniques Used on Metal Pipes Bent by the Induction Process
Bending metal pipes is not a walk in the park. Even though they are strong and highly workable, metals can snap, break and crack when bent using poor techniques. This is why you should consider having your bends done by a fabricator specialising in induction pipe bending. More specifically, you should go for a fabricator with good post-bending treatment techniques for you to achieve the best results. Since the process involves localised heating with high-frequency electric current, the fabricator must employ high-tech cooling and post-treatment techniques. Properly cured induction bends are efficient at facilitating the flow of fluids and they last longer. On that note, here are some of the treatment techniques used by induction bending specialists:
Normalising and Tempering
Normalising and tempering are one of the common techniques used by induction bending professionals. The process begins by normalising, which involves heating the bent section to a temperature where hardening occurs. For instance, steel attains normalisation at a temperature range of 800 to 920 degrees Celsius. At this temperature, the metal forms fine grains in its structure to allow optimal strength in the bent area. The new structure also gives the metal a homogenous structure that is easy to machine. Normalising is followed by tempering, a process similar to normalising but done at a lower temperature alongside jets of cool air. The objective is to enhance the structural strength of the bend.
Solution anneal is also used as a post treatment method for bends created by the induction process. It can be used for treating a variety of steel grades in the duplex and stainless steel families. Basically, the process centres on holding the bent section at a stable, heightened temperature for a certain period. The period varies depending on the nature of the bend and the type of steel that the fabricator is working on. After holding the material at a heightened temperature, rapid cooling follows using water or jets of air. There is no need for secondary heating, unlike the normalising and tempering process.
Quenching and Tempering
Quenching and tempering are used for high yield materials such as carbon steel. The technique begins by holding the bent section at a particular temperature for a certain period. This makes the metal "thirsty" and highly responsive to a cooling medium. It is thus quenched rapidly using a cooling medium to facilitate the hardening action. After quenching, tempering or secondary heating follows with cool air to strengthen the material even further.