With the rapid development of high-temperature industrial fields, metallurgical heat-resistant steel has become the preferred material for the manufacture of key equipment in petrochemical, power, metallurgical and other industries due to its excellent high-temperature strength, oxidation resistance and creep resistance. However, the construction quality of heat-resistant steel directly affects the service life and safety of the equipment, so it is crucial to strictly follow the construction standards.
Material selection and pretreatment
The construction of metallurgical heat-resistant steel must first ensure that the material meets international or industry standards, such as ASTM, ASME or GB/T. Common heat-resistant steel grades include 310S, 309S, GH3030, etc. Different grades are suitable for different temperatures and corrosive environments. Spectral analysis, hardness testing and non-destructive testing are required before the material enters the site to ensure that the composition and performance meet the standards. In addition, heat-resistant steel needs to be preheated before welding to reduce welding stress and avoid cracks.
Welding process control
Welding is the core link in the construction of heat-resistant steel, and the process parameters need to be strictly controlled. The welding method usually adopts manual arc welding, TIG welding or laser welding, and the specific choice depends on the thickness of the workpiece and the structural requirements. The welding current, voltage and speed need to be adjusted according to the material properties, and the matching heat-resistant steel welding materials should be used. When multi-layer and multi-pass welding, the interlayer temperature needs to be controlled within a reasonable range to avoid overheating and grain coarsening. After welding, non-destructive testing of the weld (such as UT, RT) is required to ensure the quality.
Heat treatment and inspection
Heat-resistant steel usually needs to be heat treated after construction, including solution treatment or stabilization treatment, to eliminate residual stress and optimize the microstructure performance. The heat treatment temperature and time must strictly follow the material specifications to avoid overburning or underheating. The final inspection includes macroscopic inspection, hardness test and high-temperature tensile test to ensure that the product meets the design requirements.
Safety and environmental protection
Heat-resistant steel construction involves high-temperature operations, and fire prevention and scald prevention measures must be taken, and necessary personal protective equipment must be equipped. At the same time, welding smoke and waste materials must be properly handled to meet environmental protection requirements.
Mastering the construction standards of metallurgical heat-resistant steel can not only improve project quality, but also extend equipment life and create higher value for the enterprise.
