Choice between annealing and normalizing

Normalizing is to heat the steel pipe (such as seamless pipe, welded steel pipe) to 30~50 degrees above Ac3 or Accm, and cool it at a cooling rate slightly higher than annealing after keeping warm. Annealing is to heat the steel pipe to Ac3+30~50 degrees or Ac1+30~50 degrees or below Ac1, and generally cool it slowly with the furnace temperature.

Purpose of normalizing and annealing:

1. Reduce hardness, increase plasticity, improve cutting and pressure processing performance;

2. Refine grains, improve mechanical properties, and prepare for the next process;

3. Eliminate internal stress caused by cold and hot processing.

Annealing and normalizing are both heat treatments. In actual production, the choice of annealing and normalizing is mainly considered from the following three aspects.
1. Material type and composition: Select the appropriate heat treatment process according to the carbon content, alloy element content, etc. of the material.

2. Process requirements and performance requirements: Select the appropriate heat treatment process according to the specific process requirements of the product and the required material properties (such as strength, hardness, plasticity, toughness, etc.).

3. Economy and production efficiency: Comprehensively consider factors such as process cost, production cycle and production efficiency, and select the heat treatment process with the highest cost performance.