Information Center
Defects of liquid die forgings and countermeasures
Release time:
2022-04-24
The flattened pores under the skin of the workpiece will bulge bubbles on the surface due to thermal expansion when the workpiece is demoulded or heated by heat treatment. The causes are as follows: 1) too much unburned and unvolatilized paint in the concave mold, or poor exhaust from the mold chamber, causing gas generated during pouring to soak into the liquid metal; 2) The extrusion speed is too fast, causing the liquid metal to generate eddy current when filling the mold chamber and involve a large amount of gas; 3) The liquid metal contains too much gas, and the bubbles precipitated before pressurization cannot escape and are squashed under the skin.
The flattened pores under the skin of the workpiece will bulge bubbles on the surface due to thermal expansion when the workpiece is demoulded or heated by heat treatment.
The causes are as follows: 1) too much unburned and unvolatilized paint in the concave mold, or poor exhaust from the mold chamber, causing gas generated during pouring to soak into the liquid metal; 2) The extrusion speed is too fast, causing the liquid metal to generate eddy current when filling the mold chamber and involve a large amount of gas; 3) The liquid metal contains too much gas, and the bubbles precipitated before pressurization cannot escape and are squashed under the skin.
Improvement measures: 1) Appropriately increase the mold temperature and adopt spraying method to make the coating dry before pouring; 2) The pressure should be slow and stable; 3) Pay attention to the degassing operation of liquid metal; 4) The mold design should consider exhaust measures.
The appearance of cold insulation is characterized by irregular and obvious sunken linear lines (penetrating and non-penetrating) on the surface of the workpiece, with small and long shapes and a development trend under the action of external forces.
The reasons for its formation are as follows: 1) multiple ladles are poured at multiple points at the same time, so that the two metal flows are butted, but they are not completely fused and there is no inclusion between them, and the combination of the two layers of metal is extremely weak; 2) Multi-ladle pouring is sequentially poured, and the flow interruption time of the front and back two packages is too long; 3) The mold temperature is low.
Improvement measures: 1) Appropriately increase the mold temperature and extrusion pressure; 2) When multiple bubbles are poured in sequence, the flow between the two bubbles should be avoided.
Related News
Welcome to call our 24-hour service hotline, wholeheartedly for your service!
Address: No.18, Shangdun East Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province
E-mail: tongqing@forgings.net.cn
Our Brand
Copyright© 2023 Jiangyin Tongqing Machinery Manufacture Co., Ltd. Powered By www.300.cn business license
E-mail： tongqing@forgings.net.cn
We look forward to your call for consultation！