Carburising as Post-treatment Method for Pipes Bent by the Induction Method

Post-treatment of metal bends done by the induction process is one of the most important stages. It ensures that the bend formed on any metal pipe will be able to stand up to high levels of friction and abrasion. Particularly, pipes carrying high volumes of fluid flowing at high speed are at risk considering how much abrasive force they have. Thankfully, you can rely on carburising to treat your metal pipes after bending them using the induction process. The following discussion centres on carburising as a treatment technique for metal bends done by induction:

What is Carburising?

Essentially, carburising refers to the addition of carbon on the surface of stainless steel at an elevated temperature. There two reasons for adding carbon to the surface of a steel bend done by the induction process. First, the additional carbon hardens the steel in the bent area. During the induction bending procedure, the pipes are heated to a very high temperature. This causes structural changes in the metal's grain, softening the bent section. Adding carbon content hardens the softened area. Secondly, carbon restores the strength and ductility of steel so that it has good resistance to wear and fatigue during use.  

What are the Various Methods of Carburising Used by Fabricators?

There are different techniques used in the carburising process. They include:

  • Liquid Carburising- Liquid carburising refers to a technique where the fabricator submerges the heated steel section in an environment that is rich with liquefied carbon. The bath is primarily composed of cyanide and molten salts, which help to introduce the carbon contents into the hot sections of the pipe. This process relies on diffusion of carbon molecules into the steel where it is needed to produce a hardening effect. Ideally, you should go for a fabricator who uses a non-toxic bath because of the safety issues posed by cyanide.
  • Pack Carburising-this method involves packing the steel section in an environment that has high carbon content. In most cases, carbon powder and cast iron shavings are used to create the high carbon content environment. Once the bent section has been packed in the desired environment, heating follows to give off a reducing agent in the form of carbon monoxide. The reducing agent triggers a reduction reaction on the surface of the steel pipe, producing carbon. This carbon then diffuses into the steel pipe where it is incorporated into the structure of the bent steel to deliver a hardening effect.

Contact a company like Inductabend Pty Ltd for more information and assistance.