Views:0 Author:Site Editor Publish Time: 2020-07-24 Origin:Site
There are many heat treatment methods for couplings. The common ones are anti-rust and blackening on the surface, quenching and tempering in order to change the hardness of steel parts，This article is mainly about nitridation treatments that are not commonly used.
Nitridation is the process of nitriding the steel surface.When the ammonia gas is heated, active nitrogen atoms are decomposed and penetrate into the steel.Nitriding temperature is performed in the range of 500-600 ° C , and generally takes 20-50 hours, while the nitriding depth is only 0.3-0.5mm,after nitriding no need heat treatment again.
Nitriding has several different goals:
(1) improve hardness and wear resistance;
(2) Improve fatigue strength;
(3) Improve the corrosion resistance.
1. Nitriding to improve hardness and wear resistance. Steels suitable for this type of nitriding treatment materials containing alloy elements, such as aluminum, chromium, molybdenum, manganese,marked as 38CrA1A, 38CrMoA1A, etc.After treatment, the surface hardness can reach HV1000-1110 (equivalent to HRC65-70), and its hardness can support to 600-650 °C without reduction. The disadvantage is nitriding time too long, while the thin nitriding layer bears less load.
2. Nitriding to improve fatigue strength;After nitriding, the fatigue will increase significantly (often it can increase by 25-35%).Therefore, it is usually using in the structural parts that under varying loads, such as internal combustion engine crankshafts and various gears.Can use ordinary alloy structural steel. Such as 18Cr2Ni4WA and 34CrNi3Mo steel, etc. for nitriding
3. Nitriding to improve corrosion resistance to be more durable coupling.If only to improve the corrosion resistance, any type of steel can be nitrided.Low carbon steel is usually carried out at 620-700 ℃, and the depth of nitrided layer is 0.025-0.06mm.High carbon steel is at 620-800 ℃, and the depth of nitrided layer is 0.01-0.04mm.In many cases it can be instead of nickel plating, galvanizing and bluing.Generally processed parts are instrument parts, lead screws, small shafts and gears, etc.During our business experience,usually those type neednitridation,telescoping shaft coupling,u joint shaft coupling universal shaft coupling motor shaft coupling,boat shaft coupling,pipe flexible coupling