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Precautions in the operations of tungsten carbide anvils
Release time:2013-01-17

1.Elimination of internal residuall stress

Before the use of tungsten carbide anvils, the anvils should undergo an ageing process to eliminate internal residual stress. They can be aged naturally for more than one month and of course the longer the better. They can be alternatively baked and oil bathed at a temperature of 180-220oC. Good results can not be achieved if the temperature is too low, and oxidation will occur on the surface of anvils if the temperature is too high. The ageing time is normally around one week.

2.Instruction for assembling anvils

The steel ring and the carbide anvil should be installed with a rational shrinkage range and their conicity should be identical with a contact area of over 90% in order that the anvils stay in a state of elasticity while under a high pressure. Other parts that are in contact with the anvils during installation shall be in contact with the facets of the anvils instead of point or line contacts to avoid the local concentration of stress.

3.Requirements for the equipment using carbide anvils

The system`s pressure shall not exceed 85 MPa. The presses for synthesization must have good manufacturing and adjusting precision and the stability of presses should be insured without any leakage in the system. The synchronism and centricity must be guaranteed with a deviation of not more than 0.2mm.

4.Requirements for related raw materials

It is advisable to use steel rings of 45NiCrMoVa steel, since it has a suitable hardness after heat treatment, and a good finish of the inner surface is required with no deformation. The precision of big and small machined pads must meet the requirements and the surfaces of the pads must be even and smooth and the material for the pads is GCr15 steel with a moderate hardness.Pyrophyllite shall not have too much water and the baking temperature and time must be moderate in order to prevent air bleeding or air blasting in the synthesization due to the moisture and the bad pressure transfer of pyrophyllite. Baked pyrophyllite must be stored in a thermostat chamber. The sealing electric conducting steel rings must be of good quality without any rust and they are to be baked at 150oC and stored without any contact with moisture.

5.Requirements for the synthesizing process

The carbide anvils require a synthesizing process that is compatible with cavities for synthesization.

Suggestions for reducing the consumption of tungsten carbide anvils

A non-continuous operation should be avoided. Some small tests must be done when optimizing and adjusting the process.

When the process of a single piece of equipment is stable, then it can be applied to other equipment. Various methods should be adopted to reduce the pressure and temperature in the system. Measures should be taken to improve the cooling efficiency of the carbide anvils and the heating system to reduce the temperature of the anvils. And operations are to be improved as well

Handling and storage of tungsten carbide anvils

Anvils are easy to be damaged by collision and as a result after unpacking they should be individually placed in strong wooden cases or in wooden cases with partitions with one in each partition during inspection , machining and storage. They should be stored separately without any overlapping or contact with each other during assembling and installation. In the operations above precautions should be taken to avoid injuries from impact or squashing. Contamination and moisture should be avoided

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