Research On Theory About The Formation Of Rolling Skin

There are five mainly transport modes, such as the aviation, the railroad, the road, the water transportation and the pipeline. The railway transportation has the security, fast, the transportation amount big, and energy conservation environmental protection advantages. It has become the most main transportation tool on land passengers and cargo to transport by, reside in the monopoly status since the 18th century.The rail is the soul of railroad. Along with railroad high speed, heavy load developing set the more and more high request for the rail quality. Generally speaking includes two aspects, increasing the rail single heavy and enhancing the quality. The heavy rail refers to the rail used on the high-speed railway and heavily loaded railway (the concept of the modern heavily loaded railway was definite in September of 1986 by the International Heavily Loaded Association (IHHA), the heavily loaded railway must be able to let the loading capacity of every train exceed 5000t, great train in 21t passes. And the transporting amount wants more than 20 million tons circuit to be called the heavily loaded railway every year), generally mean the rail making above 50kg/m a key point only." Rolling skin" refers to scarring defects in the rail surface scar skin or ichthyoids Flake metal sheets appear at the production of heavy rail, metal matrix and connected, At the head, the waist and the base the rail the partial adherence metal thin laminated shape incrustation forms. The scar flaw outline is irregular, the concomitance scar flaw has many cracks, the scar flaw extends when compares the depth to the bottom of the rail depth, the straightening rail would have the bottom crack flaw. Therefore, although the scar and the crack nature are different, but the two are interlinked, sometimes retains the scar characteristic, sometimes appears the curving crack bunch, sometimes a combination of both, this related with the scar's size, depth and distortion degree. Rolling skin mainly has pack scar, point clip scar, massive scarring, and other types of jagged scarIn this paper uses the technical route which the big production and the laboratory unify. Takes a sample in the big production, in the laboratory using the Metallographic microscope, the electron probe X-pray microscope, and electron microscope to observe the heavy axle flaw test specimen the macroscopic and the microscopic appearance ,analysis of the qualitative and quantitative relationship. The examination project mainly has: Chemical composition analysis; Surface defect metallographic analysis. The inclusion, the organization examine; Pearly piece spacing; Flaw ingredient analysis and so on. The findings showed that in the heavy axle surface scar formation concerns with the production of the crack formation and the decarburization. Meanwhile in smelting and in the casting process, the inevitable production inclusion, it also causes the factor which the scar forms. Combining references, we give scarring defect prevention measures, including purifying liquid steel and reasonable heating time and rolling process, and so on.