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Hello 

Does the spin velocity of the oil in the cooling bath influance in come way the hardness of the steel treated ? 

Eli,

Yes, the movement/flow of the oil has a significant impact on the rate at which heat is removed from the steel, and the rate of cooling directly affects the hardness of the steel.  ASM has many resources to help you.  I have spent 15-20 years in heat treat R&D, and I can tell you that there are dozens of variables which will all come into play here (material chemistry, material shape and size, chemistry of the oil, cleanliness of the oil, temperature of the oil, flow speed, flow direction, etc.).  Let me know if you have specific questions - hopefully someone will have direct experience with your specific challenges.

Hello 

Does the spin velocity of the oil in the cooling bath influance in come way the hardness of the steel treated ? 

Hello 

Does the spin velocity of the oil in the cooling bath influance in come way the hardness of the steel treated ? 

Yes, the stirring rate of oil affects quenching rate and, in turn, the surface hardness and microstructure. The stirring rate affects the heat transfer coefficient between the part and oil. As one increases the stirring speed, the quenching severity increases up to a certain point and has no effect thereafter. At this point, the heat transfer becomes controlled by heat extraction through the part rather than heat dissipation into the oil.

Hello 

Does the spin velocity of the oil in the cooling bath influance in come way the hardness of the steel treated ? 

Hello 

Does the spin velocity of the oil in the cooling bath influance in come way the hardness of the steel treated ? 

Eli, there are two heat-treated steel characteristics that depend on the quenching process: hardness and depth of quench.

Level of hardness depends only on the temperature of the piece in respect to the steel M_f temperature, provided that it did not undergo any phase transformation prior to reaching the M_s temperature. Then, if the piece temperature goes below M_f, it reaches maximum possible hardness (barring any residual austenite).

Depth of quench is dictated by the rate of extraction of the heat from the component and, hence, also by the oil flow velocity around the piece.

Hello 

Does the spin velocity of the oil in the cooling bath influance in come way the hardness of the steel treated ?