Finishing processes result in changes of near surface morphology, which strongly influences the fatigue behavior of components. Especially, roller bearings show a high dependency of the lifetime on surface roughness and the residual stress state in the subsurface volume. To analyze the influence of different finishing processes on the near surface morphology, including the residual stress state, roller

In this study, the effect of Nb content on the phase transformation kinetics, microstructure, and mechanical properties of hot-rolled quenching and partitioning (Q&P) steel is investigated. The characteristics of three C-Mn-Si-Ti steels (0.18C, 2.0Si, 2.6Mn and 0.015Ti) containing 0, 0.027 or 0.061 % Nb are compared. Results reveal that grain boundary pinning by precipitates and Nb solute drag effects

Wire-and-Arc Additive Manufacturing (WAAM) is an innovative technology that involves deposition of subsequent layers of molten materials. Due to the high deposition rates, this technology is suitable for the production of large-scale complex structures. Further enhancement in the productivity can be achieved by an inter-layer cooling strategy that reduces idle time between depositions. However, the

The morphology and microstructure of intragranular pearlite in 100Mn13 high carbon high manganese steel aged at 600 °C by scanning electron microscope (SEM) and transmission electron microscope (TEM) are observed and analyzed, and the growth models describing morphology and growth process in three-dimensional (3-D) space are proposed. The results show that pearlite could nucleate directly in austenite

The effect of SiO2 and TiO2 on the crystal morphology of 60%CaF2-20%Al2O3-20%CaO type electroslag remelting (ESR) slags have been investigated by thermodynamic simulations, differential scanning calorimetry, X-ray diffraction, scanning electron microscope and energy dispersive X-ray spectroscopy. The results suggest that the addition of TiO2 and SiO2 changes the type, amount, and sequence of crystal

The use of low-density steels has become increasingly important due to the advantages they offer, such as high-strength, high-ductility and principally weight reduction. However, there are few studies regarding their weldability by conventional processes due to the metallurgical complexity of these alloys, which include kappa carbides precipitation and hot-cracking associated with the high contents

The characteristics of non-metallic inclusions (NMIs) in low-alloyed steel samples taken during ladle treatment before and after Ca-treatment were evaluated by using the Pulse Distribution Analysis Optical Emission Spectroscopy (PDA/OES) method, INCA-Feature investigations of inclusions on a polished surface of steel samples, and three-dimensional investigations of NMIs after electrolytic extraction

A commercially produced 0.15% carbon dual phase steel with 1081 MPa tensile strength was modified to create eight additional conditions using tempering or tempering plus cold rolling, processes that were shown to primarily affect constituent (martensite and ferrite) hardness as measured with nanoindentation. The effects of different martensite/ferrite hardness ratios were evaluated using tensile and

The cavity shape formed by the impinging of the supersonic oxygen jet on liquid metal surface is of importance to the converter steelmaking process. This work adopted the volume of fluid (VOF) model to numerically study the behaviour of four-nozzle supersonic jet impinging on molten steel bath in a 100-ton converter. Firstly, the model was validated by comparing the jet velocity with that obtained

Nowadays, under the context of severe resource shortage, it is urgent to develop non-quenched and tempered steel. In this study, a new method of combining rare earth cerium (Ce) and magnesium (Mg) to treat the 49MnVS3 steel with low oxygen and rather high sulfur is proposed. The inclusions modification, microstructure evolution, and mechanical properties change of 49MnVS3 steel with different Ce and

In the present study, numerical simulation, regression modeling, sensitivity analysis, and optimization are implemented to analyze how the reduction rates of wustite pellets are affected by the operational variables. First, the pattern of reduction of a wustite pellet over time was analyzed by applying the grain model. Overall reduction time as a function of temperature, pellet diameter, porosity,

The development of new materials and their production processes along with the environmental constraints demand new data of high quality, especially thermodynamic and physical property data. As slags play a crucial role in metallurgical processes and recycling, the need of better understanding of the reaction mechanisms between slag and metal is also increasingly felt. High precision data and better

Oxygen lance is the key to realize the emulsification of gas–slag–metal in the converter steelmaking process, which determines successful completion of metallurgical tasks. Herein, a 3D full-size gas–slag–metal coupling model of the nozzle-twisted lance in a 120t converter is established. The behavioral characteristics of gas–slag–metal of nozzle-twisted lances (swirl angle 0°/5°/10°/15°) are studied

In the present article, the combined influence of reactive cleaning and active filtration on inclusion removal is investigated using numerical simulations. Carbon-bonded ceramic foam filters with active and reactive effect are inserted into the steel melt to remove non-metallic inclusions. In case of reactive cleaning, carbon can dissolve from the filters into the melt. As a result, carbon reacts with

Blast furnace (BF) is the most used equipment for production of iron in the world. It is charged mainly with metallurgical coke and ferrous materials. When descending inside the BF, iron-bearing materials start reducing and melting with other burden materials. This melting leads to the formation of so-called primary slags from which the final slag is formed as materials descend inside the furnace.

The non-reactive CaO–Al2O3-based mold flux system is proposed to avoid the reaction problems during the casting process of advanced high-strength steels, when conventional CaO–SiO2-based mold flux system is applied. However, new problems such as low consumption and insufficient lubrication are introduced during the industrials of CaO–Al2O3-based mold fluxes, which is closely associated with its melt

The mechanical properties after tempering and intercritical annealing of medium manganese steels with 4 wt% Mn for forging applications are presented. After forging with subsequent air cooling, heat treatments were performed, specifically tempering from 250 and 450 °C and intercritical annealing between 600 and 675 °C. Tensile properties, Charpy V-notch impact toughness, and hardness were determined