NSK bearing cooling rate and overall reduces external surface when the stress state is changed.
1.NSK bearing cooling water to speed up the principal stress direction and accelerate the workpiece outer surface cools.
To prevent distortion of the workpiece.
2. the preparatory heat treatment should be carried out, uneven parts or asymmetric should take protective measures.
3. the workpiece prior to disposal is in the hardened State. NSK bearings, alloy steel, high temperature annealing or tempering, shrinking disposal; carbon steel and low alloy steel 4C after heating water or oil cooling, plus hot-cold treatment.
4. shrink more visible for the first time, some hardening swelled the workpiece. Swell recovery factors; the second contraction contraction effect is pure; workpieces quenched when it should total contraction, not heaving Ambassador oversize.
5. steel and plastic. Less carbon in steel and alloy content.
6. small thermal conductivity, structure the workpiece. Austenitic heat expansion coefficient. Good plasticity, shrinkage effect of austenitic type steels.
7. the workpiece principal stress orientation and size than non-principal stress directions. When this ratio closer to minimum shrinkage effect.
8. Pinch increases with the increase in size, section. Section size directly affects the size and internal stress plastic workpiece. But to a certain value with increase in size, and reduced shrinkage effect is not obvious but small parts.