High-manganese steels are characterized by high ductility, strength and work hardening resulting from the formation of strain induced martensite (TRIP-effect) or twins (TWIP-effect). A third type is shear band induced plasticity (SIP) in Triplex steels. The Mn-content ranges from 15 to 30 %. Mn and additions of C, Si and Al exert a strong influence on the microstructure and the deformation mechanism and can accordingly affect both strength and ductility. The max. carbon content can be around 1.2 %. The main interest is currently concentrating on TWIP steels. Production of these grades via the conventional steelmaking routes can raise problems and, therefore, modifications and/or alternative production methods have to be applied. With respect to their extreme strength levels, high-Mn steels exhibit an extraordinary forming potential. Welding involves some specific challenges. The possible occurrence of delayed fracture is discussed. High-Mn steels have to compete with other lower alloy steels and special stainless grades with the same objective targets. Referring to this, the laboratory and industrial trials are to be continued in order to fully exploit the considerable market potential of the new steels.

A process for electroless deposition of NiP films on a transparent non-conductive soda lime glass is investigated. The process requires at least two repetitive cycles of etching and activation. The annealing process of the NiP films at 400 and 600˚C has been studied and the optimal heat treatment condition has been established. Different Ni bath with different pH has been employed to assess the NiP deposition. Characterization of the deposits by optical and scanning electron microscopy has provided information on the nature of crystallites and on the surface topography.

JSW Steel Limited is a 10.0 Mtpa integrated steel plant and 2 corex & 4 blast furnace forms the main iron making units. Sinter and pellet are the main iron bearing feed to iron making units. JSW Steel Limited operates with a 4.2x2 Mtpa pellet plant and the production rate of each pellet plant is ~500t/hr. Pellet plant utilizes 100% beneficiation plant (BP) product for pellet making. Beneficiation plant product size (pellet grade fines) is coarser (-45micron - 40 to 45%) in nature. Optimum particle size of the raw material is required to get the desired properties of the pellets. BP plant has set up two number of ball mill to get the optimum particle size for pellet making. Pelletisation studies were carried out in laboratory by varying the ball mill discharge size from 52 to 68% -45micron size to optimize the pellet grade fines size to achieve desired physical and metallurgical properties of the fired pellets. The desired physical and metallurgical properties of the pellets were obtained with the iron ore fineness 64% -45micron size due to presence of well balanced mineralogical phases.

Failure assessment was made on cylindrical pressure vessels containing longitudinal weld misalignment performing finite element analysis (FEA) utilizing the Ansys software package. A 20° section of the cylindrical shell wall was modeled utilizing the plane strain element (plane 182) with the longitudinal weld in the centre of section. The weld misalignment was introduced by shifting the position of the cylindrical section on one side of the weld relative to the other section. Failure pressure estimates from FEA based on the global plastic deformation are found to be in good agreement with existing test results on vessels made of Afnor 15CDV6 steel and maraging steels.

Steel history and its chronological progress have been reviewed from different aspects on many published papers, and books and it can be found on many websites. However, one historical aspect of this topic, which has received limited attention, is the gradual progress in knowledge of controlling cooling rate to get the desirable thermal and mechanical properties for the steel products. This paper presents some evidence of understanding the effect of cooling rate on the material properties from Iron Age era. It also discusses briefly the importance of determining optimimum cooling rate in enhancing the production rate.

news in steel

Divestment confirmed of Ruukki Construction’s business operations in Russia

As communicated in July, SSAB has agreed to divest Ruukki Construction’s business operations in Russia (OOO Ruukki Rus) to the Russian company OAO Salavatneftemash. The transaction has received the approval of the Russian competition authorities and has now been completed. The transaction excludes the right to the Ruukki brand.

High yield strength and close tolerances

Spanish welded steel tube specialist Bornay S.L. has ordered an HF (High Frequency) tube welding line, type RD 40, from SMS group for its Alicante works. SMS group is the single-source supplier of all technical equipment from strip preparation to the cut-off-saw.

SSAB and Kemppi create a joint digi solution to speed up the welding process

SSAB and welding solutions company Kemppi have successfully piloted sending material certificates automatically from SSAB’s SmartSteel cloud to welding equipment.

Tibnor to acquire Sanistål’s steel distribution business

SSAB’s subsidiary Tibnor has agreed to acquire the steel distribution business of the Danish company Sanistål A/S, Denmark’s second largest steel distributor. This supports SSAB’s strategic target to strengthen its Nordic home market position.