Steelmaker.ru

For manufacture of special steels and superalloys the melt shop personnel’s skills play crucial role. Quality of the product and production yield essentially depend on the qualification of production staff, and therefore the plant management organized the refresher courses for the personnel. For this purpose the researchers from Lasmet Co. (Laboratory of Special Metallurgy) were invited as lectors, as they have a great long term experience in research and development of vacuum induction melting (VIM) and vacuum arc remelting (VAR) technologies.

The general purposes of the refresher courses were:
- Supply of theoretical and practical knowledge to the personnel concerning VIM and VAR technologies
- Enhancement of personnel understanding of how any technological steps affect final metal quality and production yield
- Improving of personal’s skills and production standards

The next subjects were discussed in detail:
- Types of reference technical documentation and its use in everyday work
- Preparation for vacuum induction melting (equipment, charge)
- Influence of micro-impurities and gases on the properties of steels and Ni-base alloys; Sources of impurities and gases
- Dramatic effect of the balance between residual sulphur and desulphurisers on Ni-base alloys properties and hot workability
- Interaction of rare earth metals (REM) with oxygen and sulphur dissolved in Ni-base alloys as well as with crucible lining, crucible scale and slag during VIM
- Magnesium evaporation peculiarity during Ni-base alloys
- Technology of treatment of Ni-base alloys by REM and magnesium which ensures a good hot workability and high yield
- Peculiarities of VIM ingots pouring
- Electric arc characteristics in vacuum
- The peculiarities of consumable electrode melting during VAR
- Factors influencing the melting rate
- Melting rate control
- Energy consumption during VAR
- Impurities evaporation, removal of gases and non-metallic inclusions during VAR
- Micro-slag refining during VAR
- VAR ingot solidification
- VAR ingot quality; Causes of ingot defects

The refresher courses proved to be very useful for improving of personnel’s qualification. It was another important step to raise production standards, manufacturing efficiency and competitiveness.

Source: steelmaker.ru