Thermal cycling treatment of low-carbon martensitic-bainitic steels

1. Thermal cycling treatment of 08Kh2G2F and 08Kh2G2B low-carbon martensitic-bainitic steels leads to refinement of the austenitic grain size and, consequently, of the martensite laths to 1–2 μm and causes an increase in the uniformity of the structure in specimens with sections up to 15–20 mm. After thermal cycling treatment with induction tempering at 650°C the strength properties σt, σ0.2 increase by 180–330 N/mm2, the impact strength at low temperatures increases, and the 50% ductile-to-brittle transition temperature T50 drops. 2. Rapid induction tempering of the steels with a refined structure provides a high impact strength with more complete preservation of the hardening effect of thermal cycling treatment than with furnace tempering.