Process Flow
SHS type black annealing equipment specializes in heating steel pipe to black annealing treatment temperature, and then cooling it to indoor temperature by water. Advanced inductor heating power is new type DSP+IGBT structure energy-efficient production. It is 
IGBT inversion and employ DSP do full digital accurate control, full air cooling structure (inductor water cooling) reduces system loss. It has set with  self-protection and self-diagnostic function. It can save about 15% energy than congeneric product.
Material applied: 300series austenite, 400 series ferrite, dual-phase steel
(Note: According to pipe diameter,thickness and production speed to match power. Moreover, the steel pipes need to be pickled after annealing.)