Nondestructively Inspecting Hardening Depth, Carburized / Nitrided Layer Thickess, Hardness of Components With 3MA THD System

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Situation of Heat treatment industry

Transmission components, as well as iron and steel parts used in machines, vehicles and plant engineering are often made from ferromagnetic  materials. These components  are thermally treated and machined in order to create the desired functional characteristics for use. Determining the quality of the surface layer properties, such as hardening depth, carburized / nitrided layer thickness, hardness profile, requires the application of adequate measurement techniques. Conventional testing methods, viz. metallographic analysis, cross-sectional indention hardness profile, are used to achieve this aim. Inherent to these methods is the slow testing performance and the destructive nature of the testing procedure. Therefore, they are inadequate for in situ inspection of the boundary surface properties, during or shortly after a certain manufacturing stage in the process chain.

3MA THD Nondestructive Solution for Multi-Function Measuring of heat treatment parts

The aforementioned destructive testing methods for characterizing boundary surface layers can be superseded by a modern nondestructive testing procedure named "3MA (Micromagnetic Multiparameter Microstructure and stress Analysis)”NDT measurement technique. The procedure can be performed fully automated and can be integrated into the manufacturing process. Its high inspection speed enables to characterize and analyze materials during or directly after a production step with up to 100 percent.

As a combination of hardware and mature process engineering, 3MA comprises four micromagnetic measurement methods: ■ Magnetic Barkhausen noise analysis; ■ Incremental permeability analysis; ■ Harmonic analysis of tangential magnetic field strength; ■ Multi-frequency eddy current analysis. Carrying out these 4 methods under multiple frequencies supplies over 40 micromagnetic parameters which represent the characterization of the material structure.

By combining these parameters in a multiparameter approach,  production issues such as batch fluctuations and handling/processing tolerances can be easily managed.As the individual micromagnetic inspection quantities show differently weighted sensitivity with regard to target values and inspection quantities, the influence of disturbance variables can be eliminated or at least reduced.

Analyze hardness and depth of IHD/CHD/NHD

Steel cable applied and residual stress analysis

The 3MA NDT methods allow the fast and concurrent evaluation of several relevant quality characteristics of the material or parts.

Benefits of 3MA THD Nondestructive Measuring: ?Fast, non-destructive measuring of material characteristics. ?Simultaneous determination of multiple quality parameters. ?Continuous monitoring and documentation of quality parameters. ?Substitutes destructive testing methods. ?More cost-effective production by reducing the costs associated with testing and defects (rejects, rework, etc.). ?Complete and comprehensive integrated process monitoring. ?Custom implementation to meet special requirements (test probe design, software, etc.).

More Industrial Applications for example:

Case Hardening Quality Characterization of Gears

Special probe for Pistons‘ Hardening depth

Automated gear wheel scanner

Hardening depth of Crankshaft

For more details, please contact LAB GAGES directly.

Common Applications & Target Parameters ■ Surface hardening characterization, for quality assurance of induction, case, carburized, nitriding, laser and electron beam hardening processes,  and detection of thermal treatment defects. ■ Materials characterization and optimization ● Hardness (HV,HR, HB, etc.), Hardness Profile ● Hardened depth (SHD, IHD, CHD, NHD, LHD, EHD) ● Layer thickness and layer properties ● Microstructures Analysis