Research On The Effects Of Materials And Oxidation Conditions On The Oxidation Mechanism Of Metal Rapid Shear Extrusion Bonding

The headless rolling technology is the third leap of steel processing process,Steel production is no longer a single block,lacuna,but for continuous rolling.At present,metal connection methods commonly used mainly through the induction welding,or laser welding to achieve the goal of scale casting connection.But this method exist some disadvantages such as connection of high energy consumption,low efficiency,and the flash is difficult to remove.So,we will research and development a connection technology that can quickly shear extrusion.In the process of the connection,there is a widespread oxidation problem on materials,and the generated scale seriously affect the quality of the material's connection.So,in this paper,we study the scale which generated in the process of metal fast shear extrusion and the influence of scale on the material connection quality.It can lay a theoretical foundation for endless rolling intermediate slab solid-state shear extrusion connection technology fast development and application.This article use continuous weighing method,research Q345,40 Cr,8Cr3,12Cr5 Mo and 12Cr13,study their constant temperature oxidation behavior at 900 ?,950 ?,980 ?,1050 ?.According to the curve of oxidation weight per unit area,we deduced the Q345 steel oxidation in mid and late phase and oxidation of weight regulation,establish the dynamics equation of the oxidation of Q345 steel.The results show that Q345 steel'oxidation weight conforms to the linear rule when the temperature is 900 ?,it conforms to the logarithmic rule when the temperature is 950 ? and 980 ?,the early stage of the1050 ? conforms to the linear rule,middle type conforms to logarithmic rule.Using scanning electron microscopy and X-ray diffraction technology to analysis the scale which generated by 40Cr?8Cr3?12Cr5Mo?12Cr13 at various temperatures,and combining oxidation weight curve to determine the influence of Cr element to generate scale.The results show that under the same temperature as the increase of the content of Cr oxidation the harder,the stronger antioxidant ability.When Cr content is more than 4%,with the increase of temperature and the extension of time,the oxidation rate will further speed up.We conducted experiment,observe under 1050 ? the oxidation time is 1 s,3 s,5 s,7 s and 8 s combination of macroscopic and microscopic state,do tensile test to study the billet after oxidation time connection.The results show that Along with the increase of oxidation time,the connect quality be worse,the tensile strength be lower.When theoxidation time is 8 s,the tensile strength of billet is 0,When the Oxidation time is 1 ~ 3 s,the connection effect is the best.We established the relationship between tensile strength and the thickness of the oxide skin of Q345 steel,provide the process parameters for headless rolling intermediate slab solid-state fast shear extrusion connection technology.