Home>Bearing knowledge>Quality requirements and disadvantages of bearing steel (1)

/*728*90 created on 2018/5/16*/ var cpro_id = "u3440131";

Bearing steel quality requirements and shortcomings (1)

Source: China Bearing Network Time: 2014-09-13

/*250*250 was created on 2017/12/25*/ var cpro_id = 'u3171089';

1. The quality requirement of bearing steel. Rolling bearings should be under the stress state and high stress value such as stretching, tightening, bending, shearing, alternating, etc.; work at high speed and long time. Therefore, in the production process; bearing There are many steel quality control inspection projects; the control scale is narrow; the production process is strict and messy; the demand has certain tooling equipment, inspection methods and certain level of villain skills. In order to ensure the bearing has outstanding function and high life; The quality requirements for steel are as follows:
(1) Chemical composition: Chemical composition is the most essential element of bearing steel. The physical, chemical, mechanical functions and metallographic arrangement of steel are determined by chemical composition; the chemical composition is changed; the fundamental properties of steel are changed. Therefore, the chemical composition of bearing steel is necessary to meet the scale of the normative rules.
(2) Internal quality: can be divided into micro-quality and micro-quality.
Micro-quality: the bearing steel inside does not agree to white spots, shrinkage holes, slag inclusions, civilian metals, cracks, over-burning, subcutaneous air bubbles and other shortcomings. The internal segregation and loose control of the bearing steel are required to be within the certain scale. The interior of the steel is fine; it does not allow the defects visible to the naked eye to split the base of the steel.
Micro-quality: the internal arrangement of the bearing steel should be uniform; the purity should be high.
The internal arrangement of bearing steel refers to carbide strip, carbide net, carbide liquid precipitation and annealing arrangement. Carbide is one of the primary components of bearing steel; it exists objectively; how to make carbide spread evenly and loosely In the past few years, the primary producers of bearing steels have chosen high-temperature dispersion treatment; new processes for handling rolling and successive annealing furnace equipment. Even so; the dispersion of carbides cannot be The degree of reaching the ambition. Thus; in the norm; rules their scale of consent and level of control.
The purity of bearing steel refers to the degree of contamination of steel by non-metallic inclusions. Non-metallic inclusions are the kind of material of bearing steel matrix; it destroys the continuity of matrix; it is one of the primary reasons for the early fatigue and shedding of bearings. Therefore, the amount of non-metallic impurities in the bearing steel is as small as possible. In order to restrain and control the presence of non-metallic inclusions in the steel; in the specification; they are subjected to strict level control. In addition to the electric furnace exercise, the manufacturer Electroslag remelting; also used the electric furnace to enhance the external essence of the furnace, vacuum deoxidation, argon blowing treatment, powder spraying outside the furnace and other processes; strive to reduce the oxygen content of the steel to less than 20ppm.
(3) Appearance quality: the forming method of bearing parts; currently there are casting, turning and cold punching. According to different forming methods, there is a different degree of demand for the quality of steel appearance. In general, the bearing steel surface must not have cracks. Folding, cracking, crusting and slag inclusion. Cold drawn steel for cold punching; except for the above shortcomings; the appearance should be clean; there should be no defects such as rust and burrs. The bearing steel should not have a severe decarburization appearance. According to the different requirements of the molding process of bearing parts; in the specification; there are different constraints on the depth of the decarburization layer of different types of steel.
(4) Scale to promise public service: according to the forming process of bearing parts and the production process of steel; in the specification; the rules for the various types of bearing steel and the standard scale of public service are carried out. The standard for casting steel is usually according to GB908-72. Specification; hot-rolled steel scale public service according to GB702-86; cold-drawn steel according to GB905-82 specification; cold drawn steel wire according to YB245-64 specification.

Recommend to friends comments close window

Bearing related knowledge

Selection of sliding bearing oil from smooth bearing in casting application of motor bearing removal method
How to distinguish the authenticity of SKF bearings from the problem of NSK bearing quality

This article links to http://
Please indicate the bearing network http://

Previous:Analysis of the smoothing and sealing skills of rolling mill bearings Next:Introduction to rolling bearing steel

Basin Faucet

A Basin Faucet (also spigot or tap: see usage variations) is a valve controlling the release of a liquid that enabling washing and drying in the bathroom.

Basin Faucet,Minimalist Basin Faucet,Basin Faucet For Bathroom,Wall Mounted Mixer Basin Faucets

Kaiping Jenor Sanitary Ware Co., Ltd , https://www.jmjenorsanitary.com