Steels for Automotive Applications...

Steels for Automotive Applications Steel has been a leader in automobile applications since 1920s. Currently, steel is the primary material in body and chassis structures. It is the backbone of the entire vehicle. In cars, these days, steel makes up about 65 % weight. It plays many roles in present day vehicles. It protects occupants, provides positive driving experience, reacts to road loads, provides comforts, and provides attachment points to other components of the vehicle. As there is a high emphasis on greenhouse gas reductions and improving fuel efficiency in the transportation sector, the automobile industry is investing significantly in lightweight materials. The industry is moving towards the objective of increasing the use of lightweight materials. It is giving priority to the activities connected with the development of new materials, forming technologies, and manufacturing processes. The weight reduction is still the most cost-effective means to reduce fuel consumption and greenhouse gases. It has been estimated that for every 10 % of weight eliminated from a vehicle’s total weight, fuel economy improves by 7 %. This also means that for every kilogram of weight reduced in a vehicle, there is around 20 kg of carbon dioxide reduction. Over the last decade, a strong competition between steel and low density metals has been observed in the automobile industry due to the increasing requirements of passenger safety, vehicle performance and fuel economy. The materials used in automotive industry need to fulfill several criteria before being approved. Some of the criteria are the results of regulation and legislation with the environmental and safety concerns and some are the requirements of the automobile users. In many occasions, different factors are conflicting and therefore a successful automobile design is only be possible through an optimized and balanced solution. Around 65...

Innovation Management and Steel Industry...

Innovation Management and Steel Industry  In the current global economic conditions, effective management plays an increasingly important role in the steel industry. As changing environment stimulates evolution in the steel industry, professionally managed organizations turn to innovation management in search for vital components of effective strategies. With rising threats and uncertainties, an organization in the steel industry requires effective innovation management strategies to ensure that their position does not weaken in the industry. Definitions of innovation There is no standard definition of innovation. One can find several definitions in literature. Some examples are given below. Innovation means new, so far not known method for fulfilling new kind of needs. Each idea, proceeding matter which is new, is called innovative, because it is qualitatively different from hitherto ones. Innovation is the new competitive arena where present-day gladiators, equipped with similar information and access to similar resources, try to outsmart one another to victory. Components involved in the definition of innovation is given in Fig 1  Fig 1 Components of innovation  Defined simply, innovation is, of course, introduction of something new. It is understood that the purpose of introducing something new into a process is to bring about major, radical change. Process innovation combines a structure for doing work with an orientation to visible and substantial results. It involves stepping back from a process to inquire into its overall organizational objective, and then effecting creative and radical change to realize order-of-magnitude improvements in the way that objectives are accomplished. Innovation can also be explained by the following Innovation is finding a better way to carry out an activity It is the key to success Something novel is often described as an innovation Innovation is a process that brings together various novel ideas in a way that they have an...

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...

TRIP Steels

TRIP Steels  TRIP steels are high strength steels. TRIP stands for ‘transformation induced plasticity’.  They are new generation of low alloy steels. These steels offer outstanding combination of strength and ductility as a result of their micro structure. TRIP steels rely on the transformation of austenite grains into the harder phase of martensite during deformation for achieving their mechanical properties. The locations of these grains in the microstructure are of major importance because they influence the impact of the TRIP effect, the microstructural localization and therefore the macroscopical deformability of the material. Microstructure and composition  The microstructure of these steels is composed of islands of hard residual austenite and carbide free bainite dispersed in a soft ferritic matrix.  The retained austenite is embedded in a primary matrix of ferrite. In addition to a minimum of 5 % to 15 % of retained austenite, hard phases such as martensite and bainite are present in varying amounts. Austenite is transformed into martensite during plastic deformation (TRIP effect), making it possible to achieve greater elongations and lending these steels their excellent combination of strength and ductility. Fig 1 shows the typical microstructure of TRIP steel. Fig 1 Typical micro structure of TRIP steel  TRIP steels typically require the use of an isothermal hold at an intermediate temperature, which produces some bainite. The higher silicon and carbon content of TRIP steels also result in significant volume fractions of retained austenite in the final microstructure. TRIP steels use higher quantities of carbon than dual phase steels to obtain sufficient carbon content for stabilizing the retained austenite phase to below ambient temperature. Higher contents of silicon and/or aluminum accelerate the ferrite/bainite formation. They are also added to avoid formation of carbide in the bainite region. Silicon though a key element for the formation of retained austenite, is undesirable...