A new manufacture process on cryogenic propellant tank for large-scale reusable launch vehicle ZQ-3 based on Stainless Steel (SUS301) material via laser welding
- Paper ID
96010
- author
- company
LandSpace Technology Corporation Ltd.
- country
China
- year
2025
- abstract
ZhuQue-3 (ZQ-3) is a reusable, high payload capacity, low-cost, and highly reliable liquid oxygen-methane (LOX/LCH4) launch vehicle developed independently by LandSpace Technology Co., Ltd (referred to as "LandSpace" hereunder), which is believed to be China's first model of LOX/LCH4 reusable launcher. During the development of ZQ-3 launcher, a method using ultra-high-strength stainless steel SUS301 combined with laser welding technology has been developed for the production of the dual cryogenic propellant tanks for LOX/LCH4. SUS301 stainless steel exhibits excellent mechanical properties under both ambient and cryogenic conditions, resulting in propellant tanks with comparable lightweight performance to the aluminum tanks as conventional material for launch vehicle, which ensures the rocket's payload capacity. Test result depicts that the longitudinal weld joints of the tank body can achieve 95% (or higher) of the mechanical properties of raw materials, while the circumferential joints can reach 90% or higher. By applying raw materials with lower strength for the tank bottom, which is then subjected to tensile forming, the mechanical properties are elevated to match those of the tank body. Currently, the subject propellant tanks with the above-mentioned process have passed the constant-temperature hydrostatic tests and low-temperature liquid nitrogen tests, with flight-proven test scheduled in 2025 on the maiden flight mission of ZQ-3.