Selection of Seamless Pipe Quenching Medium

Quenching is the seamless pipe above the Ms point temperature, at an appropriate rate of cooling to the following Ms slow cooling after, access to excellent organizational performance. Quenching requires the use of quenching media. Quenching oils, water-soluble quenchants, water and brine and caustic soda are the common cooling media. However, the following selection criteria should be followed regardless of the media:

1. Based on the carbon content of steelTemperature, the low carbon content of the seamless pipe may precipitate proeutectoid ferrite, and its overcooled austenite most likely to pearlite transformation temperature higher martensitic starting point (Ms) is also higher in order to fully harden this type of steel seamless pipe, the quench medium used should have a shorter vapor film phase and the temperature at which the highest cooling rate should occur is higher. For steels with higher carbon content, the vapor phase of the quenchant may be longer and the temperature at which the highest cooling rate occurs may be lower.
2. Based on the level of hardenability of steelCold speed, poor hardenability of the steel required cooling speed; good hardenability of the steel, the required cooling rate is slower. The cooling temperature, the poor hardenability of the steel, the media require the highest cooling rate of the higher temperatures appear; while the hardenability of the steel, the highest cooling medium required medium temperature lower.
3. Based on the effective thickness of seamless pipeWhen the seamless pipe is relatively thick, in order to get a sufficiently thick hardened layer depth, the quenching medium used should have a faster cooling rate at a lower temperature. On the contrary, when the seamless pipe is thin and small, the quenching medium with low cooling rate can be used.
4. Based on the complexity of seamless pipe shapeSeamless pipe with complicated shape, especially seamless pipe with inner hole or deeper concave surface, should use quench medium with short steam film phase to reduce the quench distortion or harden the inner hole. Conversely, simple-shaped seamless pipe, you can use the steam membrane longer quenching medium stage.
5. Based on the allowable amount of distortionSeamless tube requires small distortion, quench cooling should have a narrow cooling rate, and the larger the allowable distortion, you can have a wide cooling rate. Allowable cooling rate of bandwidth, you can use the general can achieve quenching hardness requirements of the media.

A worker from a steel pipe company, which is located in China.