1. Overview
&Nbsp; Bearing steel is mainly used to manufacture rolling parts. Such as ball, roller and bearing rings and so on. They are at work, suffer a high concentration of alternating load, due to ball bearing rings and the contact area between the small, high-speed rotating along with sliding, there may be great friction. Therefore, bearing steel should have a high hardness, wear resistance and fatigue strength of steel microstructure, chemical composition requirements are very strict, otherwise it will significantly shorten the bearing life. General bearing steel with high carbon content, in the 0.95 to 1.1% range, and adding some alloying elements, such as chromium, manganese. Mostly ball annealing delivery, need to be quenched before use (about 840 ℃) and low-temperature tempering (150 ℃).
(1) manufacturing methods: the quality of bearing steel smelting demanding, and requires strict control of sulfur, phosphorus and non-metallic inclusions content and distribution, because the non-metallic inclusions content and distribution of great influence on the life of bearing steel . The higher the amount of inclusions, the shorter life expectancy. In order to improve the quality of smelting has recently been adopted by the electroslag remelting furnace smelting, and can be used to vacuum metallurgy, vacuum consumable refining new techniques to improve the quality of bearing steel.
(2) Uses: In addition to doing ball, bearing ring endures, and sometimes also used to make tools such as dies, measuring tools, taps and so on.
2. Main production plant and exported to countries and regions
China's Dalian Steel Plant, Daye Steel Plant is the production of bearing steel main producing area. At present the main exports to Hong Kong and Southeast Asia.
3. Importing the main producing countries
China mainly from Japan, Germany,Washing Machine Bearings bearing steel imports.
4. Type
China is now producing high-carbon chromium bearing stainless steel, the main steel grade are 9CR18; carburizing bearing steel, the main steel grade are G20CrMo; chromium bearing steel, the main steel are GCr15.
5. Specifications and appearance quality
Specifications are mainly round steel, flat steel, wire and so on. Steel surface shall be processed well. May not have crack, fold, scarring, and inclusion. Cold-drawn steel surface should be smooth, clean, non-oxide skin.
6. Chemical Composition
GB, YB, Japanese standard, the chemical composition of the major steel Table 6-7-24.
Table 6-7-24 on standards of major indicators of the chemical composition of steel
Standard Number steel chemical composition%
C Si Mn P S Cr Mo Ni
GB/T3086
-82 9Cr18 0.90 -
1.00 "0.80" 0.80 "0.035" 0.030 17.00 -
19.00
GB/T3203
-82 G20
CrMo 0.17 -
0.23 0.20 -
0.35 0.65 -
0.95 "0.030" 0.030 0.35 -
0.65 0.08 -
0.15
YB (T) 1
-91 GCr15 0.95 -
1.05 0.15 -
0.35 0.25 -
0.45 "0.025" 0.025 1.40 -
1.65 "0.30
JISG4805
-90 (96) SVJI 0.95 -
1.10 0.15 -
0.35 "0.50" 0.025 "0.025 0.90 -
1.20 "0.25
Note: The above steel Cu% were less than 0.25.
7. Physical Properties
The physical properties of bearing steel mainly to check the microstructure, decarbonization layer, non-metallic inclusions, mainly low magnification. Under normal circumstances are hot-rolled annealed, cold-drawn annealed delivery. Delivery status should be indicated in the contract. Steel, low times that organizations must be non-shrinkage, subcutaneous bubbles, white spots and micro pores. Center porosity, Tapered Roller Bearings generally loose no more than 1.5, no more than 2 segregation. Steel annealing organization should be a uniform distribution of fine granular pearlite. Decarbonization layer depth, non-metallic inclusions and carbide nonuniformity should comply with relevant provisions of the relevant national standards.
8. Package
To be packaged for delivery of less than 20mm in diameter, larger than 20mm can be loaded naked delivery. Of cold-drawn steel to be coated anti-rust oil. The goods before leaving the factory quality assurance should be attached to the book stating the steel furnace number, weight, size, chemical composition, testing standards and test results.
