Steel enjoys an unsurpassed wide range of properties: first of all its stiffness-strength-formability relationship contributes to featuring steel a high potential as versatile light-weight construction material. In this respect it pays to use steel, its price cannot be undercut without accepting compromises. This is topped by additional gains comprising high availability, reliability, excellent manufacturability and recyclability. Steel enjoys great popularity amongst designers, most of them are very familiar with it. In intermaterial competition, steel may not win in every single discipline, but steel is the undisputed champion in multi-discipline jobs. This makes steel an indispensable material.

High nitrogen steels are commonly known for their excellent mechanical properties, i.e. strength and corrosion resistance. A state-of-the-art production routine is P-ESR melting (pressurised electro slag remelting). It is possible to manufacture both, austenitic as well as martensitic steels suitable for forging and hot rolling. Some basic knowledge of the material peculiarities is mandatory to avoid any potential issues during plastic deformation. The following paper provides an overview of the manufacturing of HNS as well as some properties to be considered for plastic deformation.

Corrosion behavior of 19Cr-18Mn-0.69N austenitic stainless steel was studied by cyclic polarization technique in 3.5 % NaCl solution and was compared with that of other austenitic stainless steels having different compositions namely, AISI 316L and one with 14 Cr and  8% Mn, denoted 14Cr-8Mn in the following. The results showed that 19Cr-18Mn-0.69N austenitic stainless steel exhibits higher pitting resistance compared to that of other two alloys. SEM micrographs of 19Cr-18Mn-0.69N austenitic stainless steel after corrosion showed no pits at the alloy surface even when it was polarized beyond transpassive pitting potential. However severe attack was seen at the araldite-metal interface. But, in case of AISI 316L and 14Cr-8-Mn severe pitting attack was seen at the surface, whereas no attack was seen at araldite-metal interface. Critical crevice temperature for the three stainless steels was determined. 19Cr-18Mn-0.69N austenitic stainless steel was found to have good crevice corrosion resistance compared to other alloys investigated.

The total amount of solid particles as a parameter influencing the viscosity and the foaming properties of the slag was investigated. In this context, the amount of these particles for different process conditions was quantified. In addition, the effect of the process conditions on the total amount of the particles was studied. More specifically, some parameter studies were carried out in oder to determine the influence of chromium oxide (Cr2O3) content, calcium oxide (CaO) content, basicity and temperature on the total amount of solid particles. The interactions between the process conditions were also taken into account.

P91 steel is also known as modified 9Cr-1Mo (P91) steel is widely used as a structural material in the construction of power plant components. In high-Cr ferritic steels, toughness degradation in welds was caused by the presence of δ-ferrite phase in the martensite matrix. The δ-ferrite phase formation is influenced by factors such as chemical composition of welds, Creq and Nieq , heat input used during welding. As the δ-ferrite phase content increases there was reduction in toughness of welds below the specified requirement of 47 Joules as per the standard EN1557: 1997. The poor toughness of welds having δ-ferrite phase can be improved by prolonging the PWHT duration at 760°C. Flux system of consumables also influences the toughness of welds. Basic flux system produces welds having higher toughness than acidic flux system. This is due to microinclusion content of welds. The flux basicity, V and Nb content, and ferrite factor are interrelated and presented as a line diagram. The present study discusses about the role of chemical composition, and welding processes (SMAW and FCAW) on the formation of δ-ferrite phase in welds and its influence on toughness of welds.

news in steel

China: Steel bloom caster modernization for greater production flexibility

Nanjing Iron and Steel Group Co., Ltd., a leading Chinese steel producer with approximately ten million tons of steel produced per annum, has awarded SMS Concast AG an order to upgrade the four strands of continuous caster CCM4 at its Nanjing plant No. 2.

Foundry components - additional know-how from Leroy-Somer

For more than fifty years the Leroy-Somer foundry has been designing and producing grey and spheroidal graphite cast-iron components in short, medium and long production runs.

Nanjing Iron and Steel upgrades electric arc furnace with injector technology from SMS group

Nanjing Iron and Steel Co., Ltd., China, has placed an order with SMS group to supply new SMS group ConSo R6 injectors for the electric arc furnace No. 3 in Luhe, Nanjing. Erection and commissioning of the equipment are scheduled for 2019.

MMK relies on PQA® for quality management across all processes

Magnitogorsk Iron & Steel Works (MMK), Russia, has placed an order with MET/Con, an SMS group company, for the implementation of the quality management system PQA® (Product Quality Analyzer).