Study of Factors Affecting Tensile Strength of Grey Cast Iron

Tensile strength of a material is the capacity of material to withstand tensile force without failure. Tensile strength is important mechanical property of material which gives direction to use it for proposed application safely. It is very important parameter considered in designing sound product. Grey cast iron carries properties like high compressive strength, castable, good machinability, good abrasion resistance, high thermal conductivity, resist to expand under high temperature. Tensile strength of grey cast depends mainly on carbon content, steel scrap % used, inoculation, graphite morphology, cooling time. Present paper summarizes study of factors affecting tensile strength of grey cast iron. With the study of factors affecting the tensile strength of cast iron it is very helpful to achieve required tensile strength by controlling the factors affecting strength of the material. While studying and experimenting on the behavior of tensile strength, clear idea comes into the picture how the strength is affected.

Increasing the Efficiency of Production of Synthetic Cast Iron Castings

The main factor that determines the content of the development strategies of a modern foundry is the use of modern technological processes, especially melting technology. First of all, this applies to the production of iron castings, which make up 65% of the mass of all alloys. Since 2000, in Russia, there has been a sharp decrease in the amount of pig iron scrap, the cost of foundry and pig iron and the cost of their transportation have increased significantly. This led to an increase in material costs in the production of castings from synthetic iron, which was mainly obtained in crucible induction furnaces of industrial frequency (ICT). In addition, problems began to arise with the use of acidic lining as the cheapest and most durable, since an increased amount of steel scrap began to be used in the metal charge, and for this reason the melting temperature was raised above 1450 ° C. The durability of the lining has sharply decreased, and downtime associated with its replacement has increased. All this had a negative impact on the efficiency of the production of synthetic iron castings.

Optimal control of the blowing mode parameters during basic oxygen furnace steelmaking process

The oxygen converter is intended for production of steel from liquid cast iron and steel scrap at blowing by oxygen. Nowadays, Basic Oxygen Furnace process is the main method for steelmaking. The main disadvantage of the basic oxygen furnace is the limited ability to increase the part of scrap metal. The task of the proposed approach is to control of the blowing mode parameters to establish the optimal level of CO2 that will ensure a minimum specific cost of steel in the presence of restrictions and boundary conditions of basic oxygen furnace steelmaking process. A model predictive control taking into account the constraints on the input signals and the quadratic functional is proposed. The design of Model Predictive Control is based on mathematical model of an object. This approach minimizes the cost function that characterizes the quality of the process. The result of the automatic control system modeling shows that the Model Predictive Control approach provides retention of carbon dioxide level when oxygen consumption is changing. The obtained quadratic functional is optimized to find the optimal control of blowing parameters.

An Economic Model to Assess Profitable Scenarios of EAF-Based Steelmaking Plants under Uncertain Conditions

The steelmaking processes are considered extremely energy-intensive and carbon-dependent processes. In 2018, it was estimated that the emissions from global steel production represented 7–9% of direct emissions generated by fossil fuels. It was estimated that a specific emissions value of 1.8 tCO2 per ton of steel was produced due to the carbon-dependent nature of the traditional blast furnace and basic oxygen furnace (BF-BOF) route. Therefore, it is necessary to find an alternative solution to the BF-BOF route for steel production to counteract this negative trend, resulting in being sustainable from an environmental and economic point of view. To this concern, the objective of this work consists of developing a total cost function to assess the economic convenience of steelmaking processes considering the variability of specific market conditions (i.e., iron ore price, scraps price, energy cost, etc.). To this purpose, a direct reduction (DR) process fueled with natural gas (NG) to feed an electric arc furnace (EAF) using recycled steel scrap was considered. The approach introduced is totally new; it enables practitioners, managers, and experts to conduct a preliminary economic assessment of innovative steelmaking solutions under market uncertainty. A numerical simulation has been conducted to evaluate the profitability of the investment considering the economic and environmental costs. It emerged that the investment is profitable in any case from an economic perspective. On the contrary, considering the environmental costs, the profitability of the investment is not guaranteed under certain circumstances.

Comparative Study on the In-Ladle Treatment Techniques for Nodulizing the Iron’s Graphite

The objectives of this research is to study and understand the nodulizing of ductile iron using in-ladle treatment process. Among the more common nodulizing agents is magnesium (Mg) which is conventionally added to the cast iron by combining suitable alloys of one or both of these elements with molten cast iron. Depending on the characteristics of each master alloy used as nodulizer, different treatment methods and techniques are used, among these, the most widely used being in-ladle, in-mould, and flow-through, the first being the most used. This research deals with the parameters, that affect the quality of ductile iron produced using in-ladle treatment process. The parameters involved are the percentage of magnesium–ferrosilicon (Fe–Si–Mg) used and the nodulizing technique. In-ladle treatment used consists of a deep pocket into the bottom of ladle, in which magnesium–ferrosilicon is placed into it together with a steel scrap barrier (steel sheets) or calcium carbide. This study, take into account, the degree of assimilation of magnesium, which shows the performance of the chosen process, depending on the nodulizer used and the temperature of the treatment.

A Study on the smelting process of low carbon steel scrap and sponge iron in medium frequency induction furnace for production of front bumper beams

MS1200 steel grade is now widely utilized in the automotive sector because it is a good solution for the current trend of vehicle chassis frame construction. This research presents a technology procedure for producing MS1200 steel grade from low carbon steel scrap and sponge iron – a product of MIREX Vietnam. The smelting using up to 30 % sponge iron briquettes combined with low carbon scrap, FeSi, FeMn, FeCr, FeTi,… was realized in a medium frequency induction furnace. The heat treatment for forged steel was performed to obtain required properties. The steel product has the following properties: tensile strength σb = 1280 MPa, yield strength σ0.2 = 990 MPa and impact toughness ak = 769 J/mm2, that meets the need of industrial use.

An Evaluation of the Microstructure of High-Aluminum Cast Iron in Terms of the Replacement of Aluminum Carbide with Titanium Carbide or Tungsten Carbide

One of the problems with recycling is that of widespread contaminated steel scrap with an unwanted aluminum addition. In this paper, we will present a specific solution to this problem. The implementation of high-aluminum cast iron production has been considered. This cast iron is a cheap material resistant to high temperatures; additionally, it has increased abrasion resistance. Despite the above-mentioned advantages, high-aluminum cast iron has not been widely used in the industry so far, due to the difficulties encountered during machining and the occurrence of the phenomenon of spontaneous disintegration. The paper presents a method for replacing aluminum carbide with titanium carbide or tungsten carbide. This research shows that the carbide replacement procedure is sufficient in stopping the phenomenon of self-disintegration of a casting made of high-aluminum cast iron. Moreover, a new material was obtained, i.e., high-aluminum cast iron with precipitates of hard tungsten carbide and flake graphite. When considering the abrasive resistance of this material, flake graphite can be treated as the natural lubricant phase and tungsten carbide precipitation, as the hardening phase.

Circular Steel: How Information and Actor Incentives Impact the Recyclability of Scrap

Recycling plays a vital role in preserving resources like steel and consequently in a circular economy. Scrap dealers and steel mills, the main business units in this system, often encounter opposing financial and sustainability incentives in using scrap as feedstock because regular sorting and scrap-preparation infrastructure cannot deal with the increasing complexity of steel scrap. Mismatches between the inputs and the target composition of the recycled steel result in trade-offs that favor the economics at the expense of resource efficiency. By examining literature and interviewing several actors, different scrap characteristics were identified as dimensions of scrap quality. Quality is typically associated with chemical composition, which is important, but this study aims to elaborate the concept of quality further and to connect it to the realities of scrapyard operations. Industry actors have different definitions for desired content, physical condition, shape and size, and homogeneity, based on their needs. Very few studies examine these details. Additionally, the relationship of quality and the level of information about the characteristics of the material was established. Having more definitive information on scrap increases opportunities for resource-efficient actions. This work offers an alternative perspective on how to address issues pertinent to recycling. Graphical Abstract