STEEL TWIST (St. 42) STRENGTH CHANGES ANALYSIS WITH QUICK HEATING AND COOLING USING PLAIN WATER AT 800”C TEMPERATURE
Steel twist is often happened on machine component that is the axis that its main function to continue power and circle. So, the choosing of axis substance that will be used is very important to know the strength of its twist, so it is safe to be used. This research is the research continuation that is has ever done before. Steel as technical material is often used as machine components, the strength to the external load is very needed to be known before it is used. The external load that is often happened to the machine component is twist load, pull load, bend load, and pound load. This research analyze the standard steel twist St.42 after it is heated at 800’C temperature with quick cooling, using plain water that is done in material test laboratory, majors in Machine Technical, Bali State Polytechnic. The research is aimed to get how big is the St.42 steel strength changes and its twist angle changes after being heated until 800’C and being quick cooled by using plain water, infact it becomes more tough and becomes more twist endure compared to standard St.42 steel. Its strength changes shows there is twist strength improvement until 38, 549%, that is from 503,7021855 (N/mm2) becomes 697,8735409(N/mm2), thus the steel angle arises, even the specific twist angle arises from 0,959385993 (‘/mm) becomes 9.403372244(‘/mm).