Study On The Correlations Between The Micro Shear Test And Formal Tensile Test With Welded Joint

Welded technique is always an important criterion of the industrial technical competence about one country. Because of the complicated micro-structure, narrow zone and sufficiently varied properties in welded joint, it is a critical but difficult means to measure accurately the every zone mechanical properties for ensuring the weld quality of the product, furthermore, improving the welding technology. Micro shear test is a new way to measure the mechanical properties of non-balanced quality materials. This way could measure the properties and shows the distribution law of every narrow zone of the welded joint, especially the bond line. Therefore, it is a significant subject to study on the correlations between the micro shear test and formal tensile test with welded joint. So it could take full advantage of the micro shear test.In this research, perform skillfully on the micro shear test, hardness test and impact test to the dozens of welded joints whose intensity level are from 450 MPa to 1050 MPa among engineering applications; collect together the mechanical properties of the weld metal zone, bond line and heat-affected zone; apply the theory of least squares methods function approximation, probability and mathematical statistics; and respectively obtain the curve regression experienced formula of for converting shear intensity Ï„h intohardness test parameter HV₅, HV_l0 and shear toughness W₅ into impact toughness a_K at every narrow zone. The interrelated coefficients of these...