Effect of Sulfur Content on the Inclusion and Mechanical Properties in Ce-Mg Treated Resulfurized SCr420H Steel

To clarify the effect of sulfur on inclusions and mechanical properties of Ce-Mg treated resulfurized SCr420H steel. Laboratory experiments were conducted to prepare steels with sulfur contents as 0.01%, 0.06%, and 0.132%. Inclusion evolution in liquid steel, MnS precipitation during solidification, and tensile test results of steel after quenching and tempering were investigated. The results showed that due to the limitation of mass transfer in molten steel, composite inclusion that Ce-O-S wrapped by Ce-Ca-Mg-Al-Si-O, which was named transition state inclusions, can form quickly after adding Ce-Mg lump to the molten steel. As the homogenization of molten steel, the difference of sulfur content in steel can lead to the transition state inclusions transformed into different inclusions. With the increase of sulfur content, the quantity of MnS increased significantly, and the morphology of MnS transformed from “stick” to “dendritic + fishbone”, and then to “fishbone”. Tensile test results and fracture analysis indicate that the decline of inclusion spacing as the increase of sulfur content leads to a shorter physical path of crack propagation in steel. Therefore, the increase of sulfur content can bring about a decrease in the strength and plasticity of the steel. From the perspective of inclusion control, making the MnS inclusion precipitate more dispersive and increasing the distance between inclusions can be considered as a method for preventing the decline of mechanical properties in steel with high sulfur content.

The Improvement of the Operational Characteristics of the Ventilated Front Brake Discs

Wear and crack resistance are important operational characteristics of brake discs. The paper presents the most optimal concentration of sulfur in cast iron, which ensures its least wear, and discusses the implementation of the front brake discs manufacture from Gh190 cast iron having 0.11 ... 0.13% sulfur content at contrast to the 0.01 ... 0.03% sulfur content, and proves the change leads to a significant increase in wear and frictional properties of the discs. In the course of research, it is found that the increase in the crack resistance of brake discs is possible due to the improvement of the thermophysical properties of cast iron with the increase in the carbon content (up to 3.55 ... 3.60%) and the decrease in the silicon content (up to 1.45 ... 1.50%), while the carbon equivalent is constant.

High Strength, Epoxy Cross-Linked High Sulfur Content Polymers from One-Step Reactive Compatibilization Inverse Vulcanization

Inverse vulcanization provides a simple, solvent-free method for the preparation of high sulfur content polymers using elemental sulfur, a byproduct of refining processes, as feedstock. Despite the successful demonstration of...

Optimization design of marine seawater desulfurization technology

Because ships burn inferior fuel, the emission of ship exhaust gas has a great impact on the environment. In order to effectively deal with the increasingly strict limit of sulfur content and SO2 emission of ship fuel by the International Maritime Organization. On the basis of analyzing the characteristics of SO2 gas soluble in seawater, this paper studies and compares the current industrial seawater desulphurization technology and other flue gas desulfurization technologies, puts forward the feasibility of the application of seawater desulphurization technology in the exhaust gas emission of marine diesel engine, and theoretically designs and calculates seawater desulphurization technology is pointed out.