1. Material processing differences
A105
It is a common carbon steel that meets the ASTM A105 standard. The carbon content in the chemical composition is about 0.35% (medium carbon steel) and has not undergone special heat treatment.
It is suitable for valve manufacturing under general working conditions, such as pipes, flanges and accessories.
A105N
It is subjected to normalizing heat treatment based on A105. "N" means normalizing process.
After heat treatment, the grain is refined, which improves the mechanical properties and corrosion resistance of the material.
2. Comparison of performance and applicable scenarios
| characteristic | A105 | A105N |
|---|---|---|
| Strength | Meet the basic strength requirements | Improving yield strength and tensile strength through normalizing |
| Corrosion resistance | ordinary | Better, suitable for environments containing corrosive media |
| Applicable working conditions | Normal pressure and temperature environment | High temperature, high pressure or severe working conditions (such as steam systems, heavy-duty valves) |
3. Differences in standards and specifications
The ASTM standard stipulates that the chemical composition of A105 and A105N is exactly the same, and the only difference is the heat treatment process.
In the naming rules, "N" means normalizing treatment, and other labels such as "A" (annealing) and "NT" (normalizing + tempering) correspond to different processes.
4. Selection recommendations
A105N is preferred in scenarios involving high-pressure steam (such as pressure reducing valves), frequent opening and closing (such as stop valves), or long-term exposure to corrosive media.
A105 can meet the needs of conventional pipeline systems, but it should be selected with caution when high mechanical performance requirements are required.
