The annealed state is a kind of seamless steel pipe delivery state, that is, the steel pipe is annealed and heat-treated before leaving the factory. A metal heat treatment process in which the metal is slowly heated to a certain temperature, maintained for a sufficient time, and then cooled at an appropriate rate (usually slow cooling, sometimes controlled cooling).
Seamless pipe annealing state subdivision
1. High temperature annealing and slow cooling state
This state is suitable for strengthening the ultrasonic reaction or obtaining stable dimensions, after heat treatment at a time and temperature similar to that required for solution heat treatment, and then slowly cooling to room temperature. It is also suitable for users to machine products before solution heat treatment. No mechanical properties specified.
2. Thermomechanical treatment state
This state applies to deformed products subjected to special thermomechanical treatments. It is also suitable for products that need to be superplasticized before solution heat treatment by the user.
3. Homogenization state
This state is used for continuous casting drawn billets or strips. In order to eliminate or reduce segregation, high-temperature hot-dip treatment is required, which improves subsequent processing deformability and response to solution heat treatment.
Causes and elimination methods of annealing waste products of seamless pipes
1. The performance is unqualified.
(1) Causes: a. The material card does not match; b. The process is not executed correctly; c. The equipment process is faulty.
(2) Elimination methods: a. Only when the material card is consistent can the furnace be annealed; b. Strictly implement the annealing process; c. Strengthen inspections and find problems in time.
2. Coarse grain
(1) Causes: a. Slow heating rate; b. Unsatisfactory annealing temperature; c. Too long holding time.
(2) Elimination method: adopt high temperature, fast, short-term annealing process
Seamless pipe annealing state subdivision
1. High temperature annealing and slow cooling state
This state is suitable for strengthening the ultrasonic reaction or obtaining stable dimensions, after heat treatment at a time and temperature similar to that required for solution heat treatment, and then slowly cooling to room temperature. It is also suitable for users to machine products before solution heat treatment. No mechanical properties specified.
2. Thermomechanical treatment state
This state applies to deformed products subjected to special thermomechanical treatments. It is also suitable for products that need to be superplasticized before solution heat treatment by the user.
3. Homogenization state
This state is used for continuous casting drawn billets or strips. In order to eliminate or reduce segregation, high-temperature hot-dip treatment is required, which improves subsequent processing deformability and response to solution heat treatment.
Causes and elimination methods of annealing waste products of seamless pipes
1. The performance is unqualified.
(1) Causes: a. The material card does not match; b. The process is not executed correctly; c. The equipment process is faulty.
(2) Elimination methods: a. Only when the material card is consistent can the furnace be annealed; b. Strictly implement the annealing process; c. Strengthen inspections and find problems in time.
2. Coarse grain
(1) Causes: a. Slow heating rate; b. Unsatisfactory annealing temperature; c. Too long holding time.
(2) Elimination method: adopt high temperature, fast, short-term annealing process
