| Duplex stainless steel refers to a type of steel that contains both austenite and ferrite in steel,so its performance combines the advantages of austenitic stainless steel and ferritic stainless steel,and is widely used in petrochemical,papermaking,and petroleum And other industrial fields.In order to explore the hot-rolling and compounding process of 2205 duplex stainless steel/Q345carbon steel clad plate,this paper first uses thermal simulation to systematically study the high-temperature thermal deformation behavior of 2205 duplex stainless steel and Q345 carbon steel.The systematic study of different temperature and strain rate The influence of 2205 and Q345 structure and performance explored the evolution of 2205 microstructure.Then the 2205/Q345 hot compression composite experiment and the double pass thermal compression composite experiment were carried out,the purpose of this study is to provide theoretical basis for the optimization of hot rolling process and forging process of 2205 duplex stainless steel composites.Operate as follows:The Gleeble-3800 thermal simulation test machine was used in the experiment,and then the thermal deformation behavior and thermal compression of 2205 duplex stainless steel and Q345 carbon steel were systematically studied through electron backscatter diffraction?EBSD?,scanning electron microscope?SEM?and other technical means.Compound process.The sample size is unified as a cylinder with a diameter of 10 mm and a height of 15 mm,and the reduction is unified as 60%.There are three main stages of research:The first stage:Study on the hot deformation behavior and microstructure evolution of 2205 duplex steel and Q345The Gleeble-3800 thermal simulation test machine was used to perform single-pass uniaxial compression tests on 2205 and Q345 cylindrical specimens at different deformation temperatures and deformation rates.The test temperature was 850??1100?;the strain rates were 0.01s-1?10s-1.The true stress-strain curve was obtained,and then the constitutive equations of 2250duplex stainless steel and Q345 carbon steel were derived,and the hot working diagram was established.Then,the specimen was cut along the compression direction and the electron backscatter diffraction?EBSD?was used to study the microstructure evolution at different strain rates and temperatures.Study 2205dual-phase steel at the same temperature,with the increase of the deformation rate,the austenite phase content decreases slowly,the ferrite phase content increases.And through the hot processing diagram,it is found that the best processing process interval between 2205 and Q345 is when the temperature is1030-1100?,the strain rate is 4.5-10s-1.Second stage:2205 dual-phase steel/Q345 hot compression composite hot deformation behavior and near interface microstructureBased on the conclusion of the first study,a single-pass thermal compression composite test was performed on the 2205 and Q345 cylindrical specimens at different deformation temperatures and deformation rates using a Gleeble-3800 thermal simulation test machine.The test temperature was 850?1100?;strain rate is 0.01s-1?10s-1.The microstructure evolution and dynamic recrystallization behavior of 2205 duplex stainless steel and Q345 carbon steel during the hot compression composite process were studied,and the Arrhenius type constitutive equation of 2250/Q345 hot compression composite was successfully established.Then,EBSD and SEM were used to analyze the structure after hot compression composite deformation,respectively,to provide thermal deformation parameters for actual production.This stage verified the process parameters obtained in the first stage,and by analyzing the microstructure evolution of the two materials in the hot compression composite process,it was finally obtained that the best process parameters for 2205dual-phase steel/Q345 hot compression composite can be obtained The interval is:temperature 1050?1100?,strain rate 4.5?10s-1.The third stage:2205/Q345 dual-pass thermal compression composite thermal deformation behavior and near interface microstructureBased on the research of the first two stages,the best processing interval of2205/Q345 was obtained.However,because rolling at high temperatures in industrial production will cause the material to have coarse grains and poor performance,high-and low-temperature double-pass rolling is usually used.In order to explore the optimal reduction ratio of two-pass rolling,2205 duplex Steel/Q345 dual-pass hot compression composite experiment,through studying its thermal deformation behavior and microstructure evolution to obtain the optimal compression ratio,provides a theoretical basis for the rolling process and heat treatment process,to achieve the purpose of guiding production practice.The specific operation is as follows:use the Gleeble-3800 thermal simulation test machine to heat to 1230°C at a heating rate of 5°C/s for 180s,and then cool to 1100°C for 30s at a cooling rate of 5°C/s for the first compression Deformation;then continue to cool to 875°C for 30 seconds at a cooling rate of 5°C/s for the second compression deformation.The deformation rate is 1s-1.The compression ratios at 1100°C and 875°C are:3:7,4:6,5:5,6:4,7:3.Through the analysis and research conclusions,it is concluded that when the compression ratio is 6:4,the composite deformation behavior of 2205dual-phase steel-Q345 dual-pass hot compression is similar,and the microstructure performance is excellent. |
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