Optimization of rotary forging temperature for molybdenum-tungsten alloy
Molybdenum and tungsten, as the same group of elements with the same atomic radius (0.136 nm), can form a complete solid solution at all temperatures and in a variety of constituent ratios. Compared with molybdenum alloy, molybdenum tungsten alloy has higher high temperature strength, recrystallization temperature, high temperature creep resistance and high temperature seismic performance. Compared with tungsten alloy, it has the advantages of better plasticity, machining property, light weight and low cost. Because molybdenum-tungsten alloy has the advantages of both molybdenum and tungsten, and has higher recrystallization temperature, its application in high temperature furnace, smelting industry and aerospace field is more and more widely, and good substitutability and high performance and price ratio make molybdenum-tungsten alloy products have a broad market application space. In particular, Mo-50W molybdenum-tungsten alloy has higher density and strength than industrial tungsten alloy, and can be used as the gas steering and guard plate of solid rocket engine, as well as the furnace bladder and heat insulation screen of high temperature furnace, etc. However, in recent years, there are few reports on the preparation methods of Mo-50W alloy and the final products.
The method of rotary forging for molybdenum and tungsten rod under different temperatures was studied to optimize the preparation process of rotary forging for molybdenum and tungsten rod, and the optimal rotary forging temperature was determined to achieve the purpose of improving the product yield. The effects of different rotary forging temperatures on the yield and mass loss rate of 6. 0 mm molybdenum-tungsten rod and the effects of different annealing temperatures on the microstructure of the same molybdenum-tungsten rod were investigated by using the alloy composition of Mo-50W and the raw material diameter of 21. The reasonable rotary forging temperature and annealing temperature are finally determined.
(1) The temperature of rotary forging plays an important role in the yield of molybdenum-tungsten alloy. When the temperature of rotary forging is between 1370 ℃ and 1450 ℃, the molybdenum-tungsten rod is easy to split and the yield is only 70%~75%.When the rotary forging temperature is 1450~1530 ℃ or above, no splitting of molybdenum and tungsten rod occurs, and the yield of molybdenum and tungsten rod reaches more than 90%.
(2) Effect of rotary forging temperature on the mass loss rate of Mo-W alloy. With the increase of temperature, the mass loss rate increases. Combined with the product yield, mass loss rate, cost and other factors, the optimal rotary forging temperature of Mo-50W alloy is 1450~1530℃.
(3) For the molybdenum-tungsten alloy with rotary forging temperature between 1450℃ and 1530℃, the annealing temperature of molybdenum-tungsten alloy is 1450℃, and the recrystallization process is basically completed. After that, with the further increase of annealing temperature, the grains begin to grow.
