Twinning Induced Plasticity Steels...

Twinning Induced Plasticity Steels  Twinning induced plasticity steels, also known as TWIP steel, are a class of austenitic steels which can deform by both glide of individual dislocations and mechanical twinning. The steels are fully austenitic and nonmagnetic, with no phase transformation. These steels represent one of the types of new families of high strength steels which have been developed in recent years to meet the increased demands of weight reduction in automobiles. The formation of deformation twins causes a large degree of deformation. This deformation mode is the reason behind the naming of this group of steels. First steel based on plasticity induced by mechanical twinning was found in 1998 which had strength of 800 MPa with a total elongation of above 85 %. These values varied with deformation temperature, strain rate and chemical composition. Composition and micro structure  TWIP steels contain a high level of manganese (Mn) content. These steels are normally composed of iron (Fe), 15 % to 30 % manganese (Mn), 1 % to 3 % silicon (Si) and 1 % to 3 % aluminum (Al). The steels usually contain large concentrations of Mn because it is crucial to preserve the austenitic structure based on the ternary system of Fe-Mn-Al. The main influence of Mn in TWIP steels is to control the stacking fault energy (SFE) and therefore the deformation mode. The addition of aluminum to Fe-high Mn TWIP steels is because it increases SFE significantly and therefore stabilizes the austenite against phase transformations which can occurs in the Fe-Mn steels during deformation. Furthermore, it strengthens the austenitic micro structure by solid solution hardening. Al also improves corrosion resistance. Silicon sustains the austenite transformation into martensite, since its lowers the SFE and increases the number of stacking faults that are nucleation sites for martensite. It also...

Employees Satisfaction, Engagement and Employees Satisfaction Survey...

Employees Satisfaction, Engagement and Employees Satisfaction Survey  Employee satisfaction is the terminology used to describe whether employees are happy and contented and fulfilling their desires and needs at work. Many measures claim that employee satisfaction is a factor in employee motivation, employee goal achievement, and positive employee morale in the workplace. Employee satisfaction, while generally a positive for the organization, can also has a drawback if mediocre employees stay because they are satisfied with the work environment. Employee satisfaction is a measurement of an employee’s happiness with current job and conditions. It is a facet of employment that is seldom discussed, but is a very important element in any workplace. It is important for an organization to monitor and understand satisfaction levels. The level of satisfaction employees feel toward their job is directly related to how successfully they perform their job, how long they remain at their current place of employment, and most importantly, it impacts the collective culture of the organization. Employee satisfaction does not measure how much effort the employee is willing to expend. Employee satisfaction research has shown that employee satisfaction has positive correlations with the business performance as shown in Fig 1. Fig 1 Correlation of employee satisfaction with business performance Employee engagement is a newer concept that has been adopted within the past decade as global competition skyrocketed, ‘lifetime employment’ faded into oblivion, and organizations looked to more directly align employee performance with organizational goals. Employee engagement is a measurement of an employee’s emotional commitment to the organization. It takes into account the amount of discretionary effort the employee makes on behalf of the organization. While the exact definitions of employee satisfaction and employee engagement may differ from organization to organization, it is generally agreed that satisfaction refers to how...

Factors affecting Coke rate in a Blast Furnace Jun29

Factors affecting Coke rate in a Blast Furnace...

Factors affecting Coke rate in a Blast Furnace  BF is a counter current reactor in which the reducing gas is produced by the gasification of the carbon of the BF coke with the oxygen of the hot blast injected via tuyeres in the lower part of the furnace. The reducing gas flows upwards reducing the iron bearing burden materials charged at the top of the furnace. Coke rate is the parameter for the consumption of BF coke which is measured in kilograms of BF coke consumed per ton of hot metal produced. Blast furnace (BF) coke is a key material for BF ironmaking, acting as a major energy source (fuel), a reductant, a carburization agent and a permeable structural support. There is no other satisfactory material available, which can replace, fully or partially, BF coke as a permeable support of blast furnace charge. BF coke is the most important raw material fed into the blast furnace in terms of its effect on blast furnace operation and hot metal quality. A high quality BF coke is able to support a smooth descent of the blast furnace burden with as little degradation as possible while providing the lowest amount of impurities, highest thermal energy, highest metal reduction, and optimum permeability for the flow of gaseous and molten products. Introduction of high quality BF coke to a blast furnace results in lower coke rate, higher productivity and lower hot metal cost. Role of coke in improving the BF performance is shown at Fig 1. Fig 1 Role of coke in improving BF performance A realistic assessment of the likely performance of coke in the blast furnace operating with or without injection technology includes those properties of coke that reflect its resistance to degradation under the chemical and...

Ferritic Bainitic Steels...

Ferritic Bainitic Steels  Ferritic bainitic steels are also known as FB steels. These steels are one of the types of advanced high strength steels which have been developed for automotive application. Since these steels have two phases, hence these steels are also a type of dual phase (DP) steel. FB steels are mostly available as hot rolled products. These steels are normally cold-drawn. Ferritic bainitic range of hot rolled high strength steels has been developed to meet weight reduction requirements of the automobiles. . They are fully killed steels and are usually available in four strength levels namely FB 450, FB 540, FB 560 and FB 590. FB family of steels extends the HSLA range of micro alloyed steels to include products combining high ultimate tensile strength (UTS) with excellent formability. Typical additions for grain refinement in these steels are Al (aluminum), B (boron), Nb (niobium), and Ti (titanium). These elements are added individually or in combination. Nitrogen (N) binding is also used sometimes. FB steels are with soft ferrite and hard bainite. They have a microstructure of fine ferrite and bainite. Their micro structure is finer than the typical DP steel. Strengthening is obtained by both grain refinement and second phase hardening with bainite. The micro structure of FB steels gives these steels a marked improved ductility. Fig 1 shows a typical microstructure for the FB steel. Fig 1 Typical micro structure of FB steel  FB steels are utilized to meet specific customer application requirements that require stretch flangeable (SF) or high hole expansion (HHE) capabilities for improved edge stretch capability. SF capabilities of FB steels are based on their ferrite bainite micro structure. The micro structure is usually even more finely tuned to be SF. This characteristic can be measured by the...

Customer Satisfaction Survey...

Customer Satisfaction Survey  Customer satisfaction is the key to long term success for an organization. If the customers of the organization are not happy then the organization will lose them to the competitors and lose out on the sales revenue. Understanding the customers and their needs goes a long way towards the provision of excellent customer service and high customer satisfaction. Customer satisfaction is not something that can be presumed. In fact, it is a thing which needs to be measured through customer satisfaction surveys. While customer satisfaction surveys are a good way to determine what the customers think about the organization, products, or services, they also help to find out the satisfaction or dissatisfaction of the customers with the products and services of the organization. Customer satisfaction surveys are also the best way to uncover customer needs, their likes and dislikes, what they think about the prices, how well the organizational employees are serving them, why they cancel their orders with the organization, and finding out the areas of improvement etc. The surveys go a long way to strengthen relationships with the customers and help build trust and loyalty. Learning what the customer needs and whether or not they are being met is arguably more important than having a great product, because a great product is not necessarily great if it leaves the customer unsatisfied. With a customer satisfaction survey, the organization has the following ability. To see how customers feel about the organizational products and services To understand customer’s priorities To get knowledge about the customers’ perception of the organizational performance and its customer service To understand organizational performance relative to the customers’ priorities To see how customers feel about the market, and what they need To obtain useful data for a...