Characterization of Heat Treatment

Heat Treatment: Tuning of material properties

Heat treatment is a process or a combination of processes to treat metallic components. The components, commonly made of steel(s), are temporarily heated to specific temperatures. Taking into account the rate of heating and cooling, the material properties of a component can be altered and improved. The presence of certain agents can lead to changes in the carbon or nitrogen content of the component. In all heat treatment processes, there are several decisive and important factors: Time (heating and holding time), temperature, atmosphere, and quenching or cooling conditions.

In principle, there are two kinds of heat treatment processes: processes resulting in a thorough change of the microstructure and processes that result in merely changing regions close to the surface of the component. Examples of the former would be thermal processes, such as annealing and hardening. Examples of the latter, thermochemical processes, would be diffusion and coating processes, such as carburization, case hardening, nitrating, boriding.

The mechanisms used for heat treatment vary considerably between different groups of materials, e.g. between aluminum and steel. Therefore, the material group has to be taken into account.

Typical Challenges when Heat Treating

App. Martensitic microstructure
Martensitic microstructure

Typical Tasks when Heat Treating:

  • Reduction of stresses or strains within the component, e.g. as an intermediate step in cold forming
  • Targeted adjustment of the material or component properties that are essential to their later use, e.g. hardness, ductility, tensile strength, resilience to wear
  • Achieving certain qualities that other processes cannot produce, or produce only with difficulty
  • Tailoring of material properties within a component

The goal is usually an increase in the component or tool’s durability, and therefore an increase in efficiency. These demands cannot be met without a targeted change of material properties by heat treatment.

 

Simulating Heat Treatment

App. Heat treatment of a generator shaft (Source: Saarschmiede)
Heat treatment of a generator shaft (Source: Saarschmiede)

Why is simulating heat treatment so worthwhile?

A simulation of heat treatment is primarily about the prediction of the material properties (PreMaP) that can be achieved by heat treatment. Predictions of distortions caused by the heat treatment can also be of interest.

A high-alloy steel that has been incorrectly heat-treated can have technological properties inferior to a low-alloy steel that has been correctly heat-treated. High-quality, correctly treated steel will, however, always have properties better suited for its intended use. To manufacture high quality products, the efficient control of these energy-intensive processes is important. This includes the appropriate use of controls and regulators, burner technology, and an attuned combination of various refractory products (such as refractory bricks or high temperature wool).

Heat treatment is an energy-intensive process. Simulation-based process optimization offers all companies using heat treatment, as a step in manufacturing, a great potential to save costs. This applies especially to commercial heat treatment plants whose services are based on heat treatment technology.

Simulating the process reduces the amount of experimentation required during process design and process optimization. It also helps to smooth trial runs and the prototyping process. Elaborate processes such as material testing, (which destroy the component used in the trial run) and microsections also become unnecessary. Through simulation, typical mistakes such as too much or too little hardening, cracks from residual stress or too much distortion can be discovered before they are made.

Our Solution for Heat Treatment

Module Heat Treatment in Simufact Forming

For the simulation of heat treatment processes, Simufact Forming with its module Heat Treatment allows you to define the necessary parameters easily and clearly. For global and local heating and cooling processes, times, temperatures, and heat transfer coefficients can be set. This makes it possible to easily simulate entire heat treatment cycles consisting of heating, holding, transport, cooling, pausing, reheating, holding, transport, and cooling in one single process.

The necessary material parameters can be generated by the programs from our partners Sente Software (JMatPro) and GMT (MatILDa). Example material data is included in the software module.

Take advantage of Simufact Forming for your heat treatment processes

  • Shorter development times with fewer trial runs
  • Comprehensive process understanding
  • High process stability and quality
  • Predictions of component properties
  • Avoid quench cracks
  • Prediction of the necessary allowances for hard machining
  • Check for the necessity of hard machining
  • Broaden the product range
  • Optimal coordination of the individual process steps
  • Fewer defective parts
  • Extensive material databanks

 

Modeling Entire Process Chains

You can also couple the heat treatment simulations with those for forming and joining to simulate the entire process chain required to manufacture your component.

 For a functional analysis of Simufact Forming Heat Treatment, please read our product description:

Simufact Forming Heat Treatment