The list of operations for the technology introduction:
- selection and placing of equipment for thermal working of metal in existent conditions;
- technologies of products manufacturing in accordance with all existing strength classes: At400 - Atl200 under STO ASChM7-93; GOST 10884-94 and international Standards ASTM A615, ENV 10080, DIN488, BS 4449, SFS 1215 and other;
- training, support and technology observance control of thermo-mechanically strengthened rolled section manufacturing (reinforced bars and wire rod No.6-No.40).
The process of thermal and mechanical strengthening of reinforced bars is conducted after the rolling mill in a special facility (thermo strengthening line). After a rapid water cooling of a rod, the upper hardened layer (martensite) is formed; meanwhile the core preserves its structure – austenite. Then within a short period of time a temperature self-adjustment of the outer layer and the core centre takes place due to the gradient of both parts’ temperatures. Thus the martensite layer undergoes self-adjustment.
Final formation of a rod structure occurs on the cooling bank.
The necessary level of steel's mechanical properties is achieved by:
- update of thermo strengthening line assembling scheme;
- consumption and pressure of water in thermo strengthening line;
- temperature of metal's self-tempering;
- speed of rolling on a mill.
Advantages of this technology:
- manufacturing of products in accordance with all existing strength classes including international ones: At400 - Atl200 under STO ASChM7-93; GOST 10884-94 and ASTM А615, ENV 10080, DIN488, BS 4449, SFS 1215 etc.;
- reduction in costs of expensive alloying additions in steel-melting manufacture;
- manufacturing of reinforced bars, which combines durability and plastic properties with good welding ability.