The Preliminary Experimental Study Of The Pull-pressing Weary Characteristic On GDL-1, The High Tenacious New Material

In recent years, with the significant progress of transformation theoretic research in the bainite and the practical application, the researchers have developed a series of air-cooling bainite steel. Because the air-cooling bainite steel has many merits,such as the ingredient simply, the hardness highly in the air-cooling , the distortion dehiscence slightly and the cost low, the air-cooling bainite steel obtained the widespread application in the industrial production. At present, there are the massive research to the new bainite steel in the tenacity aspect, but few studies in the weary performance aspect, particularly high cycle weary behavior studies to this kind of steel.This article researched the high cycle characteristics of new bainite steel (GDL-1) under the normal temperature.It has carried on two kinds of endurance tests: the long crack experiment and the symmetrical tension test.The long crack experiment includes the fatigue cracking expansion experiment and the threshold value experiment. The experiment uses the air-cooling GDL-1 steel at the different tempering temperature, and carries on it under(R=-l) the permanent load. The purpose of experiment is to draw fatigue cracking expansion speed (da/dN )and fatigue cracking threshold value (â–³Kth) under for quite different temperature, thus obtains the general rule of fatigue cracking expansion of this material.The symmetric tension fatigue test uses the GDL-1 steel which is cementatited and tempered in low temperature. The experiment intent to test the the weary performance of the cementatited GDL-1 steel.The main content of the test is to measure the S-N graph and fatigue limit of the material. Then according to the test result, analyzed the possible factors which affect the weary performance of cementation GDL-1 steel.The research on long crack expanding rules are conducted emphatically in the first half part of pape.The test results indicated,with the raise of tempering temperature ,the crack expansion speed of the new bainite steel (GDL-1) appear to reduce. It was because the long crack expanding speed relates to the yield strength and the strong tenacity. With the tempering temperature increasing , The yield strength and the plasticity of new material GDL-1 simultaneously enhance.Therefore...