GB/T 32255-2015 in English

In-depth interpretation of the national standard for high-temperature pressure-bearing martensitic stainless steel and alloy steel general castings

Analysis of the background of standard formulation and technical evolution

With the increasingly stringent requirements of modern industry for pressure-bearing components used in high-temperature and high-pressure environments, traditional ordinary steel can no longer meet the performance requirements. Corrosion, wear and stress problems in high-temperature pressure environments have put forward higher requirements for materials. Martensitic stainless steel and alloy steel have become the preferred materials due to their excellent mechanical properties, good corrosion resistance and high-temperature stability.

The GB/T32255-2015 "High-temperature pressure-bearing martensitic stainless steel and alloy steel general castings" standard is formulated based on relevant technical research results at home and abroad, aiming to provide unified technical specifications for casting valves, flanges, pipe fittings and other components in high-temperature pressure environments. This standard combines international advanced experience and is optimized according to China's actual use needs.

Interpretation of main technical requirements

Comparative analysis of standard framework

This standard has a high similarity with relevant international standards (such as BSEN10213 and ASTMA217), mainly reflected in:

• Chemical composition requirements: It is basically consistent with BSEN10213, with the range of molybdenum (Mo) and nickel (Ni) content increased.
• Mechanical properties: Higher than or equal to the requirements of ASTMA217, especially the yield strength at high temperature.
• Heat treatment specifications: The temperature range of normalizing and tempering is clarified to ensure the uniformity and stability of the material structure.

Implementation suggestions

To ensure the effective implementation of the standard, the following measures are recommended:

1. Supply chain management: Casting suppliers should establish a complete raw material inspection system to ensure that the chemical composition meets the requirements.
2. Production process control: Manufacturing enterprises need to be equipped with advanced heat treatment equipment and perform heat treatment operations in strict accordance with the standards.
3. Testing and certification: Third-party testing agencies should regularly conduct sampling inspections on castings, especially mechanical properties and non-destructive testing.
4. Training and Exchange: Organize industry technical exchange meetings to share standard implementation experience and best practice cases.

Through the above measures, the quality level of high-temperature pressure-bearing martensitic stainless steel and alloy steel general castings can be effectively improved to ensure their reliable performance under complex working conditions.