The Research Of Brazing Application For Measuring Installation Of Fast Neutron Experimentation Reactor

The measuring installation of fast neutron experimentation reactor includes stress-strain and temperature measuring installation. The applied base metal is stainless steel 304, thermocouple wires (the material of the wires cover is stainless steel 304), stress-strain leads (the material of the leads cover is Inconnel 600). The most important technology for measuring installation of fast neutron experimentation reactor are as the followings: the function maximum temperature is at 400℃, the brazing temperature shall be below 800℃, the joints intensity must be higher than 120MPa at 350℃, leaking rate is 6.7×10^-7pam/s. The brazing of the stress-strain leads and thermocouple wires are implemented at the site. So the requirements for flexibility and reliability are extremely high, and the acceptable rate must be 100%. In conclusion, the project is a real challenge to modern brazing technology. And the selection of brazing method, brazing material and the brazing processing are all key factors.In this paper, many brazing methods are compared, and the induction brazing method is chosen to do experimentation for the project--brazing application of measuring installation of fast neutron experimentation reactor of China. Proper brazing alloy and flux are selected excellently on the basis of parent metal and in service temperature. With the analysis of microstructure and mechanical property, it is discussed the effects of two sets of different processing parameters on microstructure, blowing hole and the tension mechanical property at normal and high temperatures(350℃).The results shows that the processing parameters such as brazing temperature and temperature holding time are play a great role on microstructure and blowing hole of the joints while using BAg001KD brazing alloy and QJ102 flux. So it's the key factors to determine the intensity of the joints. Many experiments shows that the special heating processing: step heating, can keep the blowing hole and brazing slag away from the joint structure and the joints intensity can satisfy the original design. The experimental results provide the basis for the brazing of fast neutron reactor.