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The foreign mechanical trade bearing heat treatment method is introduced ‘ One)


25th November 2008 Bearing Technology 0 Comments

The foreign mechanical trade bearing heat treatment method is introduced:

: The heat treatment is energy consumption rich and influential family and heavy polluter of the mechanical trade at the same time. In recent years, heat so that service ability and life-span that influences the part finally of handling the quality direct relation subsequent processing quality of quality. With the progress of science and technology and application in heat treatment, the development of heat treatment technology mainly reflects in several following respects:

A cleaning heat treatment

Clean the heat treatment Or the green heat treatment in environment protecting mode One of the directions of the heat treatment technical development of developed country. In order to reduce the discharge of SO2 CO CO2 dust and cinder, the heat treatment will cause pollution to the environment if the heat treatment produces waste water, waste gas, waste salt, dust, noise and electromagnetic radiation,etc. that are formed. Solve the problem of environmental pollution of the heat treatment. Has already basically stopped to use the coal to make fuel, the consumption of the heavy oil is fewer and fewer too, the ones that used light oil instead are in the majority, the natural gas remains the most ideal fuel. The combustion furnace one waste heat utilization is which reach higher level, burning optimization and empty of structures already – not fire than if you can’t control, guarantee under prerequisite burnt rationally strictly, make NOX and CO reduce to the minimum limit; Use gas carburize, carbon nitrogen ooze together and the intersection of vacuum and heat handle technology, deal with in order to reduce waste salt and include the intersection of CN- and the intersection of toxicant and pollution of the source of water in place of the intersection of salt and bath; Adopt water-solubility to quench the kerosene and replace and quench the kerosene partly synthetically, replace some mineral oil with living beings degradative vegetable oil in order to reduce the oil pollution.

2 accurate heat treatment

Utilize physics metallurgical knowledge and advanced computer simulation and detection technique, the accurate heat treatment has meaning of two respects: On one hand according to the instructions for use, materials, physical dimension of the part. Optimize the technological parameter, reach the necessary performance or potentiality to give play to the material to the maximum extent; On the other hand fully guarantee to optimize the stability of the craft, realize product quality is dispersed degree it is very small may zero And the heat treatment distorts as zero.

3 energy-conserving heat treatment

Set up professional heat, handle factory in order to guarantee, produce, it gives full play to equipment capacity to be choice of scientific management at full capacity. The intersection of heat treatment and the intersection of energy structure and, scientific production and energy conservation whether whom energy utilize effectively have factor of potentiality most. Once energy of prior choice; Fully utilize used heat, remaining energy; Adopt the low, cycle of consuming energy short craft to replace cycle long, great craft,etc. of consuming energy.

4 has not oxidized the heat treatment little

The performance of the part is improved, safeguard the atmosphere to heat and substitute and oxidize the atmosphere to heat and heat to the controllable atmosphere of controlling carbon tendency, nitrogen tendency accurately from adopting after the heat treatment. The heat treatment defect is reduced greatly such as taking off carbon, crackle,etc., heat treated precise allowance is reduced, have raised utilization ratio and machine process efficiency of the materials. It is angry to quench for vacuum to heat and vacuum or low pressure carburize, ooze nitrogen, the intersection of nitrogen and carbon, ooze and ooze boron,etc., can obviously improve quality, reduce distortion, raise the life-span together.

Mainly show in several following respects: Research of the basic theory of the heat treatment; Research of heat treatment craft and application technology; And the development of correlation technique is equipped in the new heat treatment. The heat treatment quality control of the part of the bearing is that the strictest bearing heat treatment made very great progress during 20 the coming years in the past in the whole mechanical trade.

A high-carbon chromium bearing steel is annealed

Quench the flash back to make and organize preparing for cold working and final one for the future. The conservative ball annealed craft is slightly higher than Ac1 temperature 780~810 ℃ such as GCr15 Keep warm, up to the cooling 25 ℃/ h makes emptily coldly to under 650 ℃ slowly of stove. The heat treatment time of this craft is long Above 20h [1]And the particle irregularity of carbide after being annealed, cold working and final quenching after influencing are back to organization and performance. Later, according to the intersection of subcooling and the intersection of and the intersection of transition and characteristic of body, the intersection of person who develop and Qiu annealed craft Wen: It will be soon cold in a certain temperature range under Ar1 after heating 690~720 ℃ It is warm to go on etc., wait for and finish body to transform in the warm course into ferrite and carbide, can make directly emptily coldly after changing and finishing. The advantage of this craft is to save the time whole craft about 12~18h of heat treatment, high-carbon the intersection of chromium and ball of bearing steel for obtain the intersection of uniform distribution and detailed light even round the intersection of carbide and organization of particle at the the intersection of ferrite and matrice. The carbide in organization after handling is tiny and even. Another kind of craft of saving time is to repeat the ball annealedly: Heat after 810 ℃ to cool to 650 ℃ for the first time, and then heat after 790 ℃ to cool to 650 ℃ and make emptily coldly. Although this craft can save regular hour, craft operation is relatively in great numbers.

The body of horse of 2 high-carbon chromium bearing steels quenches the flash back

2.1 Convention horse’s body quenches tempered tissue and performance

The body of horse of the high-carbon chromium bearing steel of the convention quenches the development of the flash back craft to mainly divide into two respects: On one hand quench the impact on organization and performance of technological parameter of flash back, have neared over the past 20 years. The organization substantially as quenching in the course of flash back changes, surplus resolving, toughness and tired performance after quenching the flash back of the body,etc. [2~10 ] on the other hand quench tempered processing property, influence, size stability substantially as quenching the condition to the size and out of shape,etc. [The tissue after convention horse's body of 11~13 ] is quenched has and not dissolved for horse body, surplus body Remain The carbide makes up. Among them, horse’s tissue shape of the body can be divided into two kinds: Under the metallography microscope Enlarge the multiple and is generally lower than 1000 times Horse’s body can be divided into lath horse body and flaky horse’s two kinds of models of body to organize, it is the lath and flaky horse’s mixing tissue of the body, or the middle shape










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