The Effect of Thermal Treatment on the Mechanical Properties of Low-alloyed Molybdenum Alloys over the Wide Range of Temperatures

Structures operating at high temperatures and exposed to aggressive gaseous media are made of low-alloy molybdenum TsM-10 of the system Mo-Al-B, TsM-6 of the system Mo-Zr-B and TsM-12 of the system Mo-Zr-Hf-B [1, 2]. Alloy TsM-10 is commercially pure molybdenum deoxidized by aluminium and boron. Alloy TsM-6 is alloyed with up to 0.2 wt. % zirconium and TsM-12, is alloyed with up to 0.03 wt. % zirconium and 0.09 wt. % hafnium belongs to the heat-resistant molybdenum alloys with solid-solution hardening. The mechanical characteristics of molybdenum alloys depend on the structural state of the material and on the technological factors determining it [3-5]. In particular, in materials of this class after thermo mechanical treatment in certain regimes and after welding, particles of the second phase may form which have a substantial influence on the strength and ductile characteristics of the material [3, 6]. The article presents data on the short-time strength and ductility of thin rolled sheet made of low-alloy molybdenum TsM-10 of the system Mo-Al-B, TsM-6 of the system Mo-Zr-B, and TsM-12 of the system Mo-Zr-Hf-B in deformed, polygonized, and recrystalized states in the temperature range 290 2 270 K. It was established that heat treatment can increase the high-temperature strength of these alloys by a factor of 1.2 2.2 and 1.1 1.5, respectively.