¶ … Engineering Materials: High Strength Steel and Bus Seat Frames
The purpose of this paper is to conduct research and the review the findings. This paper seeks an understanding of the engineering material of high strength steel, the process in which it is made and the items it is used to build specifically that of bus seat frames. Over the course of the research, it is has been determined that high strength steel is effective when used in building lightweight yet safe and sturdy bus seat frames. This construct lends to the overall safety of buses using this material, specifically in existing models found in buses designed by a company called Fainsa located in Barcelona, Spain. This paper explores the process and design of these seats by looking at the process in which high strength steel is created. By understanding how high strength steel is made, one can better understand its unlimited uses an applications when it comes to designing safer vehicles used for mass transit around the world. This means doing in depth research of the process and investigating recent data regarding bus seat frames. What are the implications of using this material? Does it better the safety of bus seats or cause other problems? This paper will investigate international case studies that show different outcomes of use high strength steel as a material.
Background
The Process of Making High Strength Steel
As technology continues to change, the possibilities for application become endless. Researchers in the automotive industry are constantly looking for stronger components that weight than before. This in turn, has given birth new categories of steel grades so that the industry can meet higher strength to weight ratio requirements. The development of high- and ultra high-strength steel or UHSS grades in thin strips has progressed in recent years. The process begins by taking the original high-strength but low alloy or HSLA materials to treat with a dual phase process and fully martensitic grades in various levels (Basta and Hoon 2004). Steels can be categorized as dual-phase, HSLA and Martensitic depending on what level the process is stopped. HSLA steels vary depending on the levels of carbon and manganese. Dual-phase combine high strength and ductility through a soft ferrite microstructure with varying levels of hard martensite. By baking the steel, this makes these elements harden for structural applications. Martensitic steels are completely made of martensite and these steels are the highest strength used commercially. The fully martensitic microstructure brings steel to the hardest phase. A post quench process can be applied to make this steel more ductile and have greater formability. How these steels are handled and cut during the process also plays a part in the resulting strength. For higher grade steel and thicker gauges the coil processor will need to limit the number of cuts per coil and possibly use a two-pass preslit/final slit schedules to avoid exceeding the slitting machines capacity (Basta and Hoon 2004). This means paying attention to the knives used in cutting the steel.
The idea behind the heat treated process is that ultrahigh strength steels can be used in applications where high strength can be converted to a weight-saving advantage over other steels. Usually once the heat treatment is concluded, the steel need no further treatment. There are over twenty types of high-strength alloy steels. Some have been developed to combine improved welding characteristics along with high strength. Most have good impact properties in addition to high strength. Ultrahigh-strength steels start with a grade of 4340 and are modifications of alloy. They can be further modified depending on applications, for instance, when these steels are used for aerospace components, they are put through a vacuum-arc-re-melt process. These steels considered ultra strength because they can endure strengths greater than 180,000 psi. Once again the measure of strength is based upon the steels chemical composition. Greg Olson and his group of researchers reflect, "steel is heavy but sometimes it is the only thing that can do the job. If you can push the strength up so you use less f it, you can save a lot of weight" (2005). His team does this by combining quantum theory with supercomputing. Tests run on steel using these tools brings new insight about the effects of impurities on grain-boundary cracking in steel. This results in a steel that can be used on the space shuttle, a steel that withstands "pressure, corrosion and high temperature beyond previous steel" (Olsen 2005). Olson does this by examining...
Our semester plans gives you unlimited, unrestricted access to our entire library of resources —writing tools, guides, example essays, tutorials, class notes, and more.
Get Started Now