Development And Experimental Study Of Thermal Shock Test Device For Cladding Tube Materials

Thermal shock behavior is widely present in various equipment and instruments,and mechanical equipment works for a long time in a huge shock thermal stress environment,which brings a large degree of safety risks to the operation safety of the equipment.Thermal shock behavior is common in rocket engines,nuclear power plant shell tubes,aircraft skin materials,etc.In fact,many thermal shock behaviors occur in extreme environments,such as high temperature,corrosive environment,in order to effectively simulate the thermal shock resistance of materials under extreme working conditions,this paper proposes to develop a thermal shock test device,and based on this device to zirconium alloy Cr coating as the test object,through the analysis of the thermal shock results of zirconium alloy Cr coating,verify the thermal shock performance of this test device in different atmosphere environments.The main research work and conclusions of this paper are as follows:1.A thermal shock test device was developed.Through the analysis of the demand of the thermal shock testing machine,the modular design of the hardware system and the software system of the test device is carried out,and the hardware system specifically includes the design of the wide temperature range heating module,the air flow isolation module,the extreme speed cooling module,the mobile device module,the gas circuit module and the control circuit module.According to the control requirements,the control system mainly includes communication between the upper computer and the lower computer,parameter writing and reading programs,motor and gas loop control mode programs.2.The test apparatus was optimized and improved.Through the analysis of the problems found in the operation of the thermal shock test device,the defective structure of the extreme speed cooling module and the gas circuit module is optimized and improved,and some of the control procedures of the control system are simplified,the automatic control program of the host computer is optimized,and the single-chip microcomputer is re-selected,which improves the stability and operation efficiency of the equipment.3.Thermal shock test of zirconium alloy Cr coating in atmospheric and Ar environment was carried out.The performance of the wide temperature range heating module is verified to be stable,and the temperature error is within ±1°C.Different atmosphere environments have a significant impact on zirconium alloy Cr coating,Cr coating in the atmospheric environment oxidation cracking is serious,residual Cr coating is gradually consumed by O elements and eventually lead to matrix oxidation cracking,in the Ar environment in the form of drum packing for residual Cr coating consumption.Different holding temperatures have obvious effects on cr coatings,and the results show that the number and size of cracks on the surface of the specimen increase with the increase of temperature in the atmospheric environment,and the number and volume of the specimen surface increase with the increase of temperature in the Ar environment.