2. Conventional martensitic quenching tooling equipment Previous Next
we produce Ferro Calcium Silicon 30000mt/year,we export the material to india,japan,korea,Russia,Europe,America ect.
specification:ca:30%min si:60%min Al:1.5%max C:1%max s:0.05%max P:0.05%max
ca:28%min si:28%min Al:1.5%max C:1%max s:0.05%max P:0.05%max
Calcium Silicon,Calcium Silicon Alloy,Deoxidizer Calcium Silicon,Ferro Silicon Calcium Shizuishan Ketong Metallurgy Industry And Trade Co., Ltd. , http://www.ketongmetallurgy.com
At this stage, the conventional martensite quenching tooling equipment in China's bearing industry is uneven. From the protective medium, it can be divided into an oxidation furnace without a protective medium, a controlled atmosphere furnace and a vacuum furnace. The non-protective medium oxidation furnace accounts for about 25% of the bearing heat treatment equipment, and the non-oxidation furnace with protective medium accounts for about 50% of the bearing heat treatment equipment. The controllable atmosphere furnace accounts for about 20% of the bearing heat treatment equipment, and the vacuum furnace accounts for the bearing heat treatment. About 5% of the equipment. From the production cycle can be divided into cycle furnace and continuous furnace.
In recent decades, the development of martensitic quenching tooling equipment has focused on the following aspects:
(1) Automated production line At present, the automatic production line adopted in China can be divided into: according to its structure (or the movement mode of the workpiece in the furnace): there are muffle belt furnace, no muffle belt furnace, casting chain furnace, roller hearth furnace , drum furnace mesh belt furnace and rotary hearth furnace series production line, feeding, pre-cleaning, protective atmosphere (or controlled atmosphere) heating, quenching, post-cleaning (sometimes also carried out secondary cryogenic roller hearth furnace for secondary deep cooling ) and tempering are done automatically. The automation degree and control precision of the production line are high, and the quality of the workpiece after processing is uniform. The whole heat treatment production line can be used as part of the automatic bearing production line. Different heat treatment production lines are suitable for heat treatment of bearing parts of different types and sizes according to their structural characteristics. For example, mesh belt furnace is suitable for small and medium-sized bearing rings; rotary hearth furnace is suitable for small batch bearing rings; roller bottom furnace is equipped with automatic lifting Quenching device for bearing parts with large wall thickness; drum furnace for rolling elements and small ferrules.
(2) Multi-purpose furnace can be carburized or carbonitrided under controlled atmosphere, and quenched under protective atmosphere to complete the non-oxidative quenching process of the workpiece. It is a periodic furnace, which is mainly suitable for heat treatment of small batch and multi-variety bearing parts.
(3) Induction heating quenching and tempering equipment induction heating has the advantages of fast heating speed, energy saving and small deformation, and the processed workpiece has some properties that are not conventionally heated. At present, China's bearing heat treatment applications are mainly concentrated on slewing bearings and car wheel bearings, but there is basically no application on GCr15 steel.
(4) The vacuum furnace can reduce or avoid the oxidation of the workpiece under vacuum condition. The high-pressure gas quenching can control the cooling and deformation of the workpiece, avoiding the environmental pollution caused by oil quenching and achieving clean heat treatment. In addition, after the vacuum heat treatment, the microstructure of the workpiece is finer and uniform, the surface is consistent with the core structure, and the hardness is uniform, which is beneficial to the improvement of the bearing fatigue life. The vacuum furnace is mainly used in the heat treatment of special steel (heating temperature above 1 000 °C) and quenching of some high-precision GCr15 steel bearing parts. It is widely used in the field of bearing heat treatment in China. The development trend of vacuum furnaces is to replace oil quenching with ultra-high pressure gas quenching, and to apply vacuum carburizing furnaces to solve the application of new steels in the bearing field.
(5) Quenching cooling medium and equipment quenching medium can be divided into three categories: oil-based, water-based and gas quenching media. Oil-based quenching media are the most commonly used quenching media. Ordinary quenching oil is N32 or N22 system-wide loss oil. In order to improve its cooling performance, anti-aging performance, brightening performance and high temperature performance, the addition of refrigerant, cleaning agent, brightener and antioxidant respectively forms a fast oil. Series of quenching oils such as fast bright oil and high temperature graded isothermal oil for quenching of bearing parts of different sizes and requirements; in addition, low volatility vacuum quenching oil. A disadvantage of oil-based quenching media is that air fumes are generated during the quenching process, causing air pollution and causing water contamination during subsequent cleaning processes.