This paper discusses the major sources of residual stress generation in the steel microstructure during cooling process of as-cast steel (slabs, blooms, and billets). The stress configuration of the steel microstructure changes during quenching due to stresses introduced to the microstructure by these sources. The influence of each source in increasing the stress distribution within the microstructure during quenching is explained via corresponding formula and qualitative discussion in separate sections. The stresses accumulated during cooling may introduce the residual stress concentration zones in the microstructure of the steel.
These stress concentration zones may result in flaws, microcracks or voids formation. Consequently, it may lower the soundness of the steel and cause deviation of the thermo-mechanical properties of the cast steel from the initially designed and customer desired specified properties.

The control of non-metallic inclusions is an important tool for steel properties optimization. Most related actions of this control involve the prevision of the slag-metal and inclusion-metal equilibrium, aiming at implementation of operational practices to obtain a more adequate inclusion profile.
Computational thermodynamics has proved to be a powerful tool in the prevision of equilibrium in different metallurgical systems, especially in the metal-oxide system in question. The aim of this work is to present the application of computational thermodynamics in the study of formation and control of non-metallic inclusions in steels, mainly during secondary refining. This work shows that the careful application of computational thermodynamics can drastically reduce the empirics in the process development for the control of non-metallic inclusions in steels, contributing to an increase in the efficiency of the process manufacture, to improve the present product quality and to enable the economic development of new products.

news in steel

RRP – REYHER Rapid Prototyping supports component optimization

High costs during assembly, operations and maintenance can be avoided by optimization in the design phase, for joining technology too. The new 3D printing service RRP – REYHER Rapid Prototyping supports companies improving component design, reducing development costs and shortening time-to-market.

HYBRIT orders Norwegian electrolyzers for fossil free steel production in Luleå

Hybrit Development, a joint venture between SSAB, LKAB and Vattenfall, has ordered a hydrogen generation electrolyzer solution from Nel Hydrogen to the pilot plant in Luleå, Sweden.

Tibnor’s acquisition of Sanistål’s steel distribution business completed

SSAB’s subsidiary Tibnor has now comleted the acquisition of the steel distribution business of the Danish company Sanistål A/S, Denmark’s second largest steel distributor.

NUCOR TAPS DANIELI MI.DA. TECHNOLOGY FOR ITS STRATEGIC EXPANSION IN REGIONAL REBAR MARKETS

When exploring the opportunity to expand its presence in new regional markets in the Midwest and Southeast of the USA, Nucor immediately understood the benefits of the MI.DA. technology and ultimately chose Danieli to supply the complete technological equipment package for two MI.DA. plants, in Sedalia (Missouri) and Frostproof (Florida).