SPRING ALLOY STEEL Russian patent published in 2008 - IPC C22C38/34 C21B13/00 

FIELD: iron and steel industry.

SUBSTANCE: said utility invention relates to iron and steel making industry, in particular, to the production of spring steel used for manufacture of elastic parts used in car suspensions. The steel has components in the following ratio, % weight: carbon 0.53-0.58; silicon 1.4-1.6; manganese 0.6-0.8; chromium 0.6-0.8; aluminium 0.003-0.015; oxygen 0.0005 - 0.0030; calcium 0.0005 - 0.0020; sulphur <0.015; phosphor <0.015; nickel <0.10; copper <0.08; molybdenum <0.01; vanadium <0.01; tin <0.01, arsenic <0.005; iron and mechanical impurities being the remaining part. The steel is produced using iron-rich pellets obtained using the direct reduction method and providing the minimum contents of residual elements and impurities with a maximum total content of 0.28 % weight. It improves the machining ability, provides stability of properties during heat treatment, and allows to produce products with required performance.

EFFECT: production of spring steel with improved processibility properties and increased stability of properties during heat treatment.

2 cl, 1 ex