Heat treatment and surface engineering

Heat treatment and surface engineering

Heat treatment and surface engineering is a 2nd semester elective specialised course held at University of Ljubljana, Slovenia.


2. semester - University of Ljubljana, Slovenia


Prof. Dr. Roman Šturm


Course Points (ECTS)


Contact Information

University of Ljubljana, Slovenia

Course Overview

Module objective

The objective of the Heat treatment and surface finishing engineering course is to provide the students with the necessary fundamentals for understanding the material properties given by the available heat treatment processes. The students therefore gain knowledge about the materials used in mechanical engineering, the physical properties and the microstructural phenomena characteristic to the individual material groups, with respect to the different heat treatment processes. A special presentation is delivered of phenomena occurring in the materials and influencing the achieved properties of core and surface of treated material. This knowledge also incorporates knowing and comprehending the material data available from the handbooks.


  • The ability to assess the behaviour of materials built into a device or structure from the viewpoint of the selected heat treatment.
  • A good knowing of surface integrity yielded by different heat treatment processes and ensuring the required quality for the operation of a product.
  • The ability to evaluate the microstructural transformations in the material after different thermal and thermochemical treatments.
  • The ability to evaluate and select an optimal material with/without heat treatment, with/without surface hardening, and with/without surface protection necessary to ensure the required product life.
  • The ability to select different manufacturing technologies and heat treatments in product, device and system design and planning.

Knowledge outcome

The students acquire basic knowledge on mechanical and some physical material properties after different heat treatments. The students acquire the ability to plan the heat treatment according to the required material properties in complex operating conditions. The student attains the ability to evaluate and compare data on materials – alloys, as presented in handbooks in the form of tables or diagrams.

Syllabus outline

  • Heat treatment processes: formation of austenite upon heating, transformation of undercooled austenite, continuous and isothermal TTT diagrams, pearlite, bainite and martensite transformation. Quenching media; hardening in water, oil, water solutions and mineral salt baths, air hardening, the influences on the hardening process, thermal hardening, interrupted hardening, internal stresses during hardening, change of volume after hardening, distortions and residual stresses, determining the size of volume changes and hardening process optimisation, defects in hardening, tempering as a diffusion process, microstructural and volume change during tempering, hardening and tempering, the influences on hardening and tempering of steels, selecting the tempering temperature according to the object mass and conditions ensuring the required mechanical properties, temper brittleness, patenting.
  • Steel hardenability: Grossman method, Jominy test; cooling intensity – H-value, quantitative determination of hardenability, practical application of data on hardenability in the optimisation of heat treatment.
  • Diffusion heat treatment processes: diffusion, diffusion mechanisms, factors influencing diffusivity. Physical-chemical processes in chemothermal treatments, structural changes in the surface layer and surface properties.
  • Surface hardening: induction hardening, physical foundations, the relations between magnetic field, induction, heating, heat conductivity and mechanical effects, energy sources, thermal parameters of inductive heating of the field between heating rate and phase transformations, induction heating processes, the properties of surface-hardened parts considering the residual stresses and mechanical loads, the materials for induction hardening. Flame hardening, heating surfaces, the execution of quenching and the selection of quenching media, the optimisation of the flame hardening process, safety and protection, laser hardening and remelting
  • Electron beam hardening: microstructural changes and mechanical properties.
  • Heat treatment of steel and cast irons: cast steel, lamelar and nodular cast iron…
  • Special techniques for heat treatment of steels: Heat treatment of non-ferrous alloys based on aluminium, copper, titanium etc. Thermomechanical treatment of selected non-ferrous alloys with microstructural changes and mechanical properties. The formation of internalstresses during hardening, residual stresses and distortions after hardening, change of volume, considering the volume changes in the preparation of parts for the heat treatment, martempering, austempering, thermomechanical treatment of alloys involving polymorphous transformations, thermomechanical treatment of alloys excluding polymorphous transformations, alloy properties after different thermomechanical treatments according to the execution of the deformation processes, selecting the thermomechanical treatment processes, selecting steels for thermomechanical treatment, the equipment for thermomechanical treatment. Strain hardening and process annealing. Microstructural change in hot working considering the initial and final forming temperature and recrystallization.
  • Furnace atmosphere: controlled protective atmospheres, controlled active atmospheres, basic means used to prepare controlled atmospheres. Furnaces and equipment for heat treatment of metals in controlled atmospheres.
  • Vacuum heat treatment of metals
  • Heat treatment of metals in fluidized bed

Monitoring of student progress


[1] W. Bolton: Engineering materials technology, Third edition, Butterworth Heinemann, Oxford, 1998
[2] K. E. Theling: Steel and its heat treatment, Bofors Handbook, Butterwords, London, 1975
[3] Handbook of Thermal Process Modeling of Steels, ed. C. H. Gür and J. Pan, 2009, CRC Press, Taylor & Francis Group
[4] K. G. Swift, J. D. Booker: Process Selection, From Design to Manufacture, 2003, Butterworth-Heinemann, Elsevier, Oxford
[5] J. Grum: Induction hardening, G. E. Totten, M. A. H. Howes, T. Inoue, Handbook of residual stress and deformation of steel. Materials Park, Ohio: ASM International, 220-247, 2002.
[6] G. E. Totten: Steel Heat Treatment : Equipment and Process Design, 2nd ed. Boca Raton: Taylor & Francis, Portland, Oregon, USA, 2007.