1. What is the heat treatment method of common carbon steel seamless pipes?
Answer: Common heat treatment methods include annealing and normalizing. Annealing is to reduce hardness and improve plasticity, which is convenient for processing; normalizing is to refine grains and improve the comprehensive mechanical properties of the pipe.
2. What is the heat treatment method of high-specification carbon steel seamless pipes?
Answer: High-specification pipes often adopt quenching and tempering treatment (quenching + high-temperature tempering), which can significantly improve the strength, hardness and toughness of the pipe, making it meet the requirements of high-pressure and heavy-load working conditions. Some pipes also need stress relief annealing to eliminate welding stress.
3. What are the common defects of carbon steel seamless pipes?
Answer: Common defects include surface cracks, pits, scratches, internal inclusions, air bubbles, and uneven wall thickness. High-specification pipes have stricter defect control, and the allowable defect size is smaller.
4. How to detect the quality of carbon steel seamless pipes?
Answer: Common detection methods include visual inspection (surface defects), dimensional measurement (diameter, wall thickness), ultrasonic testing (internal defects), tensile test (mechanical properties), hardness test, and chemical composition analysis (to confirm the material).
5. What is the service life of common carbon steel seamless pipes?
Answer: Under normal working conditions (with anti-corrosion treatment, appropriate temperature and pressure), the service life is 5-10 years; if used in harsh environments (high humidity, corrosion, high temperature), the service life will be shortened to 2-5 years.
