Heat treatment stress on the influence of the quenching crack of jiaxing bearing, please experts moments

There is rotational, have HRB bearing ( ) Heat treatment stress on the influence of the quenching crack of jiaxing bearing, please experts moments. Jiaxing bearing group sales co. , LTD. ( The company) Is jiaxing bearing factory set up in the spot sales window, specializing in HRB brand bearings, facing the whole country, the existing stock 50 million yuan, covers the whole bearing, have very strong cash supply ability. Exists in quenching parts in the different parts can cause stress concentration factor ( Including metallurgy defects) For quenching cracks has promoting effect, but only in the tensile stress field ( Especially under the maximum tensile stress) Will appear, if no effect on promoting crack in compressive stress field. Quenching cooling rate is a residual stress can affect the quenching quality and determine the important factors, is also an important endowed to quenching crack and even decisive influence factors. In order to achieve the purpose of quenching, usually must speed up parts in high temperature and the cooling speed of segment, and make it more than the critical quenching cooling speed of steel can be martensite structure. As residual stress, do so because of increased can offset the organization stress of thermal stress values, so it can reduce the workpiece on the surface of the tensile stress and achieve the goal of inhibition of longitudinal crack. The effect will increase along with the speed up of high temperature and cooling speed. And, in the case of to hardening, the greater the section size of workpiece, while the cooling speed is slow, the greater the risk of cracking instead. All this is due to the thermal stress of this kind of steel increases with the size of the actual cooling speed slow down, the thermal stress is reduced, organization stress increases with the increase of the size of the final form is given priority to with organizational stress tensile stress on the surface of the workpiece, the role of characteristics. With the traditional concept of cooling slowly stress small different. For this kind of steel under the condition of normal high hardenability steel quenching can only be formed in the longitudinal crack. The reliable principles to avoid quenching crack is managed to minimize cross section inside and outside the martensitic transformation range of sex. Just practice the martensitic transformation in slow cooling is not enough to prevent the formation of longitudinal cracks. Usually can only be produced in the hardenability of arc crack, though necessary forming conditions of the rapid cooling as a whole, but it's really the reasons, but not in rapid cooling ( Including the martensitic transformation zone) Itself, but rather quenching a local location ( Determined by the geometrical structure) In high temperature and the critical temperature, cooling speed significantly slowed, so no hardening. Produced in large the hardenability of cross sectional and longitudinal split, is by the thermal stress as the main ingredients of residual tensile stress at the center of the quenching parts, and in the center of the quench hardening at the end of the piece of cross section, the first form and from outside to inside the extension of crack. In order to avoid this kind of crack produces, often use water - Oil double liquid quenching process. In the process of implementation of high temperature within the period of rapid cooling, the purpose is to ensure that only the outer metal get martensite structure, and from the perspective of internal stress, then quickly cold more harm than good. Second, the purpose of cooling later slow cooling, not primarily induce martensitic phase transformation in order to reduce the expansion rate and stress value of organization, but to minimize cross section temperature difference and cross section near the center of metal shrinkage rate, so as to achieve the stress value and eventually inhibit quenching crack is reduced. If you are more interested in jiaxing bearing factory engineers to introduce industry information or have any questions, please click on contact us page on the right side of the online customer service, or call:, you close the way of jiaxing bearing purchasing advisors. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Editor: jiaxing bearing sourcing consultant LTD. All rights reserved, The company) Reprint please indicate the source