Perforation TZM Molybdenum Alloy Top Head Material Tzm Metal Top Head

TZM Molybdenum Top Head For Perforation

1. TZM Molybdenum Top Head For Perforation Specifications:

TZM molybdenum top head is a molybdenum alloy made of molybdenum titanium zirconium  alloy for the production of seamless steel pipe mandrel head. The molybdenum alloy plug is made of molybdenum powder FMo-1 raw material added with rare earth material, and is processed through mixing, forming, shape processing, high temperature sintering and other processes. The final item has a density of 9.4g/cm3.

2. TZM Molybdenum Top Head For Perforation production equipment:

Cold isostatic pressing 

The TZM molybdenum top head that meets the requirements upside down on the material frame or stand upright on the tray for pressing. The pressing speed and dwell time have no effect on the small molybdenum top head. For the large size TZM molybdenum top head, the compaction with higher density can be obtained by slowing down the pressing speed and prolonging the dwell time. The reason for this is that the deformation process of the particle contact zone is carried out more fully and thoroughly during the pressure build-up. In general, the pressure relief speed should be slow.

However, it also depends on the size of the green compact, and the degree of influence is also different, because when the pressure is suddenly released, the compressed high-pressure air in the green compact gap suddenly expands, which is easy to burst the plug, and the elastic after-effect further promotes the plug. of rupture. Prolonging the holding time can make the high pressure gas in the compact disappear. According to the above rules, it is concluded that the forming pressure is generally above 180 MPa and the pressure holding time is above 6 min. For example, the surface of the blank with a shrinkage rate of 20% to 25% on the diameter and axial surface of the pressed blank should have a smooth arc, no pores, no edges, no cracks, and a density of 5.5 to 6.8 g/cm3.

Turning
Clamp the blank on the CNC lathe and input the turning program of the desired shape.

Sintering
The sintering process in the preparation process of TZM molybdenum top head is very different from other molybdenum products. The molybdenum top head has a high heating temperature and a long production cycle (at least 25 h for hydrogen intermediate frequency furnace and 31 h for vacuum intermediate frequency furnace). During the heating process of the intermediate frequency furnace, at about 600~1 000 ℃, a part of O, N, C impurities distributed in the grain boundary of the blank volatilizes; at about 1 200 ℃, the low melting point impurities K, Na, Ca, etc. volatilize; at 1 600 ℃ High melting point impurities Ni, Mg, Al, etc. volatilize, so choose an appropriate heating time to fully volatilize the impurities.

The holding time generally depends on the sintering temperature. The higher the sintering temperature, the shorter the holding time; the lower the sintering temperature, the longer the holding time. In this way, the powder has sufficient time and energy to complete its densification process. If the holding time is too long, the grains will grow too much and reduce its quality; if the holding time is too short, the powder will not have time to densify, that is, "under-burning", and the quality cannot be guaranteed.

If the sintering atmosphere is H2, enough attention should be paid to the water vapor in the H2. At high temperature, the water vapor and the C in the plug will chemically react to generate CO and CO2, which will decarbonize the plug and reduce the strength when the H2 is excluded from the body. and hardness. After the sintering process is completed, power off, turn off the flame, and cool down to below 60 °C to prevent the surface of the finished product from being oxidized due to early release. .

TZM molybdenum top head has excellent performance, the material has good high temperature strength and wear resistance, good thermal conductivity and resistance to shock and heat. It can meet the production of steel pipe perforation under harsh conditions, and has a wide range of applicability in the perforation technology of seamless steel pipes.

3. Use life of TZM Molybdenum Top Head For Perforation:

The life of the molybdenum top head mainly depends on the length of the piercing cone and its profile curve design, because this determines the distribution law of deformation. The length of the piercing cone completely depends on the actual length of the deformation zone, that is, it mainly depends on the total diameter reduction of the billet; in addition, the cone angle of the roll surface and the feed angle also have a significant impact. From the total length of the deformation zone, the minimum diameter reduction length before the plug required by the secondary dragging and the necessary length of the uniform wall cone and the capillary gauge circle are subtracted, and the remaining part is the design length of the piercing and rolling cone.

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