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Experimental Research On The Damage Behavior Of Steel Materials Using Magnetic Memory Nondestructive Testing Technology

Posted on:2006-04-15Degree:MasterType:Thesis
Country:ChinaCandidate:D W YinFull Text:PDF
GTID:2121360185466518Subject:Materials science
Abstract/Summary:PDF Full Text Request
In the modern society, the safe operation of key equipments and important components has been playing a role by nondestructive testing technology in industry production, traffic transportation and resource gathering. As the new method of nondestructive testing, metal magnetic memory testing technology is popular with the new testing thought exceeding traditional nondestructive testing method by inspecting early damage of ferromagnetic components, and it is paid more attention by scientific researchers all over the world. However, it is still remote for magnetic memory testing technology to fulfill the quantitative and normative testing because of its imperfect theory and testing standard.In view of the situation mentioned above, it is done for basic study with the traditional mechanics experiment and magnetic memory testing in order to gaining the characteristics of magnetic signals in the different mechanics states for several kinds of industry steels. The method of mathematics simulation provided by author is valid to achieve quantitative testing.The research is done by static tensile experiments of four kinds of steels. It includes the influence of demagnetization technology on initial magnetic memory signals, the influence of initial magnetic memory signals on the subsequent loading, changing characteristics of magnetic memory signals during elastic and plastic loading process, the difference of magnetic memory signals between on-line testing and out-of-line testing, the relation between magnetic memory signals and residue stress or working stress. The research results reveal that little fluctuation of magnetic memory curve and value of magnetic field strength can be formed after demagnetization to work pieces successfully, and magnetic memory curve gradually changes towards inclining with the increase of load. However, the change of magnetic memory curve is reverse for the work pieces without demagnetization. Magnetic memory curves of various stress levels have the...
Keywords/Search Tags:magnetic memory testing, stress concentration, magnetic domain, static tension, fatigue
PDF Full Text Request
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