Max Diedering
Metallographer, Management laboratory-Services
Senior-Expert for Metallography & refractometry

+49 8106 9941 14


Simon Löhe
Metallographer, group leader of Laboratory-Services Munich
Expert in failure analysis and metallography
+49 8106 9941 17


Robert Mertel
Graduate Engineer Materials Science
Expert metallic materials & failure analysis

+49 8106 9941 16


Heat Treatment Damages

Damages due to faulty heat treatment

One of the most important production steps in the manufacture of individual parts, assemblies or large components made of metal is heat treatment. It plays a central role in the adjustment of the material properties.

Heat treatment is a sequence of heat treatment steps in the course of which a workpiece is wholly or partially subjected to time-temperature sequences in order to bring about a change in its properties and/or its microstructure.

In addition, the chemical composition of the workpiece can be changed during the treatment. As in case hardening or nitriding, for example.

Thermal processes include hydrogen relief annealing, stress relief annealing, soft annealing, normalising, coarse grain annealing, diffusion annealing and recrystallisation annealing as well as hardening and tempering (quenching and tempering) and surface hardening.

Damage can often occur due to incorrect temperature control or the setting of the ambient medium, which not infrequently affects complete treatment batches.  

  •     Typical damages are: Incorrect strength and hardness leads to fracture or wear.
  •     Unfavourable phase formation reduces corrosion resistance
  •     Coarse grain formation lowers the fatigue strength
  •     Embrittlement due to hydrogen
  •     Unfavourable residual stresses

But problems are also to be expected during the subsequent machining of parts: punching, turning, milling, drilling, grinding, polishing are all related to the properties and the basic structure.

Our experts use samples to analyse possible causes of defects. As a rule, metallographic sections are evaluated microscopically. The microstructural images then provide our metallographers and materials experts with information about the history of a component. Heat treatment errors can thus be detected and corrective measures initiated.

Wärmebehandlung Eisen - Kohlenstoff Diagramm
Wärmebehandlung Eisen - Kohlenstoff Diagramm
Entartetes Gefüge
Entartetes Gefüge
Schliffbild Gefügeaufnahme
Schliffbild Gefügeaufnahme
Stahl härten Wärmebehandlung
Stahl härten Wärmebehandlung
ZTU Diagramm
ZTU Diagramm

Society for Materials Testing
Ensuring quality | Accompanying development | Analyzing damage | Passing on knowledge

GWP Gesellschaft für Werkstoffprüfung mbH
Georg-Wimmer-Ring 25
85604 Zorneding/München

Tel. +49 8106 994110
Fax +49 8106 994111

Handelsregister München
HRB 53245
USt.-IdNr. DE131179893

General Manager
Dr. Julius Nickl