Bearing seat has high compressive strength and fatigue limit, high hardness, high wear resistance and certain toughness, good hardenability, sulfur and phosphorus control is very strict, is a kind of high quality steel, can be made cold steel.
Specific gravity: 7.81
(1) bearing forging temperature
(1) initial forging temperature: 1150(1120) final satin temperature: 850(800) degrees.
(2) clear surface defects before forging, try to preheat before rapid heating.
(3) the blue crisp zone of 200~400 degrees should be avoided during the warm processing.Avoid entering high temperature brittle zone (> 1250) during hot working.Avoid entering the hot and brittle zone (800~ 950 degrees).
(4) tempering temperature
Bearing block 352/ low temperature tempering is used.Temperature: 150~250 degrees.Can maintain high hardness and high wear resistance under the premise of reducing the internal stress and brittleness, so as to avoid the use of cracking or premature damage.Hardness HRC: 58~ 64.
(1) low hardenability steel
The critical diameter of oil quenching of this kind of steel is not more than 30mm. It is commonly used for carbon steel, chromium steel, manganese steel and boron steel.Common grades are 45, 40Mn2, 45Mn2, 42Mn2V, 35SiMn, 40B, 40MnB, 40MnVB, 40Cr, 40CrSi, 40CrV, 50(r, rV, etc.), carbon steel hardenability is low, poor mechanical properties, generally used to make small cross section and unimportant parts;Chromium steel has better hardenability, has higher tempering stability than carbon steel, quenching temperature is wide, not easy to overheat, deformation cracking tendency is small, so it is widely used;The function of manganese steel is similar to that of chromium steel. Manganese reduces the critical cooling rate of steel and improves the strength and hardness of steel.Boron steel boron significantly increased the hardenability of steel, its performance is close to 40Cr, the critical diameter of oil quenching in 20 ~ 30mm, commonly used for automotive half shaft, worm, spline shaft.
(2) medium hardenability steel
The oil quenching of this kind of steel is directly in 40 ~ 60n, m, the commonly used steel has chromium molybdenum steel, chromium manganese steel and so on.Common grades of 35 (jrMn, 42 crmo, 35 l: rMnV, 40 CRMN, 35 crmnsi, 30 crmnsi, 35 (: rMnTi, 40 crmnti, 40 crni, chrome molybdenum steel with high hardenability, high temperature and high strength, good stability and organization, eliminate the temper brittleness, 42 crmo used to produce high strength requirement, large cross section of the conditioning parts, such as gear, large steam turbine generator shaft, the load of the connecting rod, etc., at the same time also can be made in five (:) o ℃ under the long-term work of the parts;Chromium manganese steel hardenability and strength is higher, the toughness is not reduced, 30(: rMnsi is a high strength steel, with good welding, used to manufacture high pressure blower compression sheet, high speed load sand wheel shaft and other important parts.
(3) high hardenability steel
The critical diameter of oil cooling of this type of steel is 60 ~ 100 mm.Common material brands are 30Mn2MoW, 40CrMnMo, 30(: rNi3, 37CrNi3, 40CrNiMc), 45CrNiMov, 25cr2Ni4w, etc., 40CrMnMo is a commonly used high hardenability steel, with small temper brittleness, little overheating tendency and other characteristics, used to make cross-sectional area, high strength and high toughness of the parts, such as the large heavy-duty car half shaft.