Abstract：Solar heating tube made by GH3625 alloy tube （specification：[?]4.5 mm×0.75 mm） frequently partially cracked in the process of prototype manufacture and working test. The failure tube samples were analyzed by physical and chemical test. And it was found that the main reason for the cracking of the pipe fittings was the large grain size in tube parts caused by the improper process design during the brazing process. In the process of functional testing， the intermetallic compound was precipitated at the grain boundary when it was operating for a long time at 600-800 ℃， which reduced the ductility of the pipe. And when the gas pressure in the tube reached the limit value， the cracking occurred.
Y Ding ， B Meng ， Y Gao.Effect of Solution Treatment on Microstructure and Properties of GH3625 Alloy Tubes in Different States[J]. Chinese Materials Conference,CMC 2017: High Performance Structural Materials pp 789-801
Y Gao ， Y Ding ， B Meng ， Z Dou. Research and Manufacture of Short-Flow Hot Extrusion Forming and Seamless Pipe for GH3625 Superalloy[J]. Chinese Materials Conference，CMC 2017: High Performance Structural Materials pp 609-618