Heat treatment states of Q355NE steel plate

Differences between Q355NE and Q355NE Z15 steel plates
Q355NE steel plate is a low alloy killed steel produced in accordance with GB/T1591 standard. Q355NE-Z15 steel plate is a grade of Q355NE steel plate with additional Z-direction performance. The steel plate is composed of Q yield strength in capital letters, 355 means steel plate yield strength is not less than 355MPa, N means the steel plate is normalized or normalized rolled in delivery status, and E is steel plate quality grade.

Delivery status of Q355NE Z15/Q355NE Z25/Q355NE Z35 steel plate: the steel is delivered in the status of hot rolling, normalizing, normalizing rolling or thermo mechanical rolling (TMCP).
PS: Normalizing state includes normalizing and tempering state, and thermo mechanical rolling (TMCP) state includes thermo mechanical rolling (TMCP) and tempering state.

The heat treatment states of Q355NE steel plate are respectively (normalizing, tempering, annealing, quenching, quenching and tempering).
Normalizing N: heat the steel plate to an appropriate temperature and cool it in air.
Tempering T: keep the steel plate at a proper temperature for a long time and then cool it.

Annealing A: Heat the steel plate to a proper temperature and then slowly cool it according to different heating time of materials and specifications.

Quenching Q: It refers to block cooling of steel plates in water, oil or other inorganic salts after heating and insulation.