heat treatment

Why heat treatment is important

Welding professionals will understand that this is hot work. In fact, surface temperatures of some welded materials can reach up to 10,000 degrees Celsius. With these extreme heats comes an excessive combination of potential residual stresses on welds such as shrinkage and warpage resulting in structural drawbacks, which is why heat treatment is important. 

The specialised process of heat treatment was developed to combat these detrimental effects, offering a range of impressive induction heating instruments that work to deliver premium, reliable welds with optimal efficiency. 

This article will explore more about why heat treatment is important by looking more specifically at how induction heating works to combat these effects, as well as answering a common question, “Does induction heating work on stainless steel?”

How induction heating works

The technical processes behind heat treatment are based on a simple formula that as the temperature of a metal is raised, the yield strength decreases, allowing residual stresses to be redistributed by the creep of a weld and the metal itself.

This is because when a welded material maintains stress at a high temperature, deformation begins to occur resulting in a fracture, which can even take place if the stress is less than the yield stress of the metal.

A process that has stabilised issues related to heating metal since 1916, induction heating systems play a significant role in the manufacturing industry, contributing to expedition of production thanks to the consistent delivery of high-quality results and overall reductions in expenditure. 

It was during the early 1900s and thanks to a number of melting experiments, that the Currie point, or the temperature at which certain magnetic materials undergo a sharp change in their magnetic properties, was discovered. 

These days induction heating systems like Renteca’s Miller Electric ProHeat 35 are advanced, and offer power-driven heating solutions which quickly bring metal to the required temperature and retain it, offering advantages for safety, quality and efficiency not found in other heating methods, such as open flame and resistance heating.

This is achieved as the machine induces heat electromagnetically instead of via conventional heating elements by subjecting the metal to a high frequency magnetic field, creating eddy currents and penetrating the material’s molecules to generate heat.

The ProHeat 35 is powering a heating revolution, reducing preheating time by up to 400 per cent and saving invaluable resources on projects worldwide. This liquid-cooled and highly versatile system is designed with flexibility at the fore, and features onboard temperature control making it capable of preheating and maintaining uniform heat, as well as stress relieving, shrink fitting and coating removal. 

A sole machine that reduces costs and with functions that benefit the overall working environment, the ProHeat 35 also improves safety as operators are not exposed to open flames or the explosive gases and hot elements that are associated with fuel gas heating or resistance heating.  

Additional specs:

Rated output: 35kw @ 100% duty cycle 

Output frequency: 5 to 30 kHz

Input power: 400 to 460v 3 Phase 50/60 Hz Ce

Air cooled capacity: 204 ℃

Liquid cooled capacity: 788 ℃

Rolling inductor: Single or double rolling inductor available

Dimensions (H x W x D): 669 x 552 x 993


Does induction heating work on stainless steel?

A popular choice of welded material due to its unbeatable durability, stainless steel can be used with induction heating, however, there are some technical difficulties to be aware of including its strong thermal sensitivity resulting in a resistance time which is slightly longer.

For details on Renteca’s equipment solutions which can weld austenitic stainless steel by induction, contact the skilled team of technical experts at sales@renteca.com.au.


With a skilled team harnessing over 60 years’ worth of collective experience and having supplied industries across the trans-Tasman with welders and welding equipment for almost two decades, Renteca is renowned for facilitating a wide range of projects with performance-ready certified equipment that boasts the very latest in modern technology. 

Experts in engineering comprehensive project solutions that are compliant, robust and reliable,  Renteca is proud to offer the largest range of welders throughout Australia via their faultless client engagement process of: assess > deploy > maintain > monitor. It’s this stringent system which enables Renteca to be the market-leader in supplying versatile heavy machinery solutions to the mining and resources, defence, construction, agriculture, water and manufacturing industries, plus many more. 

To contact Renteca’s highly skilled technical team for a customised solution for your next welding project, call 07 3375 4146, submit your details here, or browse the entire fleet including induction heating equipment here