Manganese in Steels

Manganese in Steels  Manganese (Mn) (atomic number 25 and atomic weight 54.93) has density of 7.44 gm/cc. Melting point of Mn is 1244 deg C and boiling point is 2095 deg C. The phase diagram of the Fe-Mn binary system is at Fig 1. Fig 1 Fe-Mn phase diagram  Mn is present in most commercially made steels. Mn plays a key role in steel because of its two important properties namely (i) its ability to combine with sulphur (S), and (ii) its powerful deoxidation capacity. Mn is undoubtedly the most prevalent alloying agent in steels, after carbon (C). Mn is intentionally present in many grades of steel and is a residual constituent of virtually all others. Mn has played a key role in the development of various steel making processes and its continuing importance is indicated by the fact that about 85 % to 90 % of all Mn consumed in the world annually goes into iron and steel making as well as in steel as an alloying element. No satisfactory substitute for Mn in steel has been identified which combines its relatively low price with outstanding technical benefits. Available forms Mn is used in steel industry in an extensive variety of product forms. These can be classified into three major groups namely (i) ferro-manganese (Fe-Mn), (ii) silico-manganese (Si-Mn), and (iii) Mn ore. There are several standard grades within each group. Fe-Mn and Si-Mn are used mainly during steel making while Mn ore is mainly used in iron making. Types of Fe-Mn and Si-Mn produced are given in article having link http://ispatguru.com/717/. High density Mn containing 96 % or 97 % Mn, depending on grade and Iron (Fe) as the principal impurity, is also used as a desirable addition agent for super alloys, stainless...

Contract and Contract Management...

Contract and Contract Management  Contract is defined in short as an agreement between two or more parties enforceable under the law. A contract is a legally binding agreement between the parties identified in the agreement to fulfill all the terms and conditions outlined in the agreement. A prerequisite requirement for the enforcement of a contract, amongst other things, is the condition that all the parties to the contract accept the terms and conditions described in the contract. Historically, this was most commonly achieved through signature, but in many jurisdictions – especially with the advance of electronic commerce – the forms of acceptance have expanded to include various forms of electronic signature. Party/parties awarding the contract are known as the purchaser or employer. Party/parties agreeing to execute or perform the contract are known as the supplier or contractor. Contracts are of several types. They are normally classified as supply contracts, service contracts, management contract, transport contract, sales contracts, purchase contracts, design and engineering contract, training contract, maintenance contract, civil contract, and erection contract etc. Contract life cycle management is defined as the process of systematically and efficiently managing contract creation, execution and analysis for maximizing operational and financial performance and minimizing risk. Contract management life cycle is shown in Fig 1 Fig 1 Contract management life cycle  A contract life cycle has two distinct phases namely pre signing phase and post signing phase. The pre signing phase consists of activities before the signing of the contract. The activities in this phase are dominated by the purchaser/employer. There is no supplier/contractor in this phase but there are bidders. One of the bidders becomes supplier/contractor after the award/signing of the contract. The activities involved in this phase are identification and approval of a requirement, preparation of a...

Solid Waste Management in a Steel Plant Sep29

Solid Waste Management in a Steel Plant...

Solid Waste Management in a Steel Plant  Steel industry in general, produces large amounts of solid wastes while processing materials through its various processes. These solid wastes have many valuable products, which can be reused if recovered economically. Steel industry throughout the world has already taken up a number of innovative measures and continues to take further for 100 % utilization of these wastes with the ultimate objective of improving the operational efficiency and economics of steel industry. These measures not only reduce the cost of waste disposal and environmental pollution but also provide substantial amount of iron ore and flux materials as well as fuel rate benefits to the existing process, thereby conserving matching amounts of raw materials. Steel industry is both capital and energy intensive and its production volumes are very high. Process chains within the industry are long. Many different technologies are applied and the industry has a significant impact on the environment. One of the major concerns of world steel industry is the disposal of wastes generated at various stages of processing. Because of natural drive to be cost-effective, there is a growing trend of adopting such waste recovery technologies which convert wastes into wealth, thereby treating wastes as by-products. This has led to aiming at development of zero-waste technologies. The technologies developed to economically convert wastes of steel plants into wealth also provide new business opportunities for prospective entrepreneurs. As per World Steel Association (WSA), the world steel industry applies the principles of reduction, reuse and recycling (3 ‘R’s) in many ways, in order to improve the sustainability of the industry. Due to this the industry has dramatically reduced need for raw materials. In the 1970s and 1980s, modern steel plants needed an average of 1.44 tons of raw...

Sulphur in Steels

Sulphur in Steels  Sulphur (S) (atomic number 16 and atomic weight 32.066) has density of 2.05 gm/cc. Monoclinic S melts at 119.25 deg C and boils at 444.6 deg C. However, S and iron (Fe) are miscible, and Fe-S binary system at one atmosphere of pressure forms a liquid at temperatures as high as 1800 deg C, far above the boiling point of S alone. Fig 1 is the phase diagram of the Fe-S binary system at 1 atmosphere of pressure.  Fig 1 Fe-S phase diagram S is an element which is always present in steel in small quantities. S in steel is introduced through iron ore and fuel (coal and coke). The removal of S during steel making is a tedious and difficult process. S is normally regarded as an impurity in steel and is required to be reduced to the limits of practicality. However steels which are to be machined need a certain minimum S content for proper chip formation. Where machining constitutes a major fraction of the end products cost, many types of steel (carbon, alloy, and less often stainless) are intentionally resulphurized just for this reason. (refer http://ispatguru.com/free-cutting-steels/) Except in those cases where it is added for machinability, or where residual S content of around 0.040 % maximum is tolerable, the usual aim during iron and steel making is to reduce S to low levels, consistent with mechanical property requirements. For high strength (HS) steel plates and for some special bar quality (SBQ) steel products, this may mean removing the S to a level of 0.005 % maximum. There are several methods which are widely used for achieving this level of S. Further, efficient removal of S from liquid steel or iron depends on specific metallurgical and thermodynamic conditions. Though...

Conflicts and Management of Conflicts...

Conflicts and Management of Conflicts  Conflicts in an organization occur due to the disagreement amongst groups of employees or individual employees. It is characterized by antagonism and hostility and is usually fueled by the opposition of one party to another. Conflict arises when one of the party attempts to reach an objective which is different from that of the other party. The elements involved in a conflict consist of varied sets of goals, principles and values of the two parties. Conflict is often inevitable in many situations. They may range from petty ones to the very serious ones which can lead to even hostility among individuals. Conflicts significantly affect employee’s morale, their turnover, and often lead to litigation. All these affect the performance of the organization either constructively or destructively. Conflict situation is an important aspect in the working of an organization. A conflict is a situation when the interests, needs, goals or values of involved employees or group of employees interfere with one another. A conflict is a common phenomenon in the place of work. Different stakeholders may have different priorities; conflicts may involve team members, departments, projects, organization and customer as well as boss and subordinate. Conflict can be due to the mismatch between organizational needs and personal needs. Often, a conflict is a result of perception. Conflict is not always a bad thing. Sometimes, a conflict presents opportunities for improvement. Therefore, it is important to understand the conflicts and the application of various conflict resolution techniques so that conflicts can be managed effectively. There is no single definition of conflict. Most of the definitions involve different factors which include (i) there are at least two independent groups, (ii) the groups have some incompatibility between themselves, and (iii) the groups interact with...