The effect of warm forging in the inter-critical temperature range between 705 and 844°C, in improving the impact toughness of an industrially important micro alloyed steel, 38MnSiVS6 was investigated. The impact properties were enhanced to as high as 148 J after warm forging in the inter critical range, as against 19 J in the steel hot rolled from 1200°C and air cooled. In addition, the strength was enhanced by about 100 MPa after warm forging. The microstructure evolution that led to the improved toughness and strength was analyzed. The significantly enhanced toughness with moderate strength enhancement in warm deformation is attributed to the increases in the ferrite content, finer ferrite grain size, finer pearlite colonies and finer interlamellar spacing. The fractography of the impact test samples in hot deformed and air-cooled condition shows poor toughness associated with cleavage facets, while the warm forged steel, showed fine dimple rupture.

研究了在 705 到 844°C 之间的临界温度范围内温锻对提高工业上重要的微合金钢 38MnSiVS6 的冲击韧性的影响。在临界温度范围内温锻后，冲击性能提高到高达 148 J，而在 1200°C 热轧和空冷的钢中则为 19 J。此外，温锻后强度提高了约100MPa。分析了导致韧性和强度提高的微观结构演变。温变形中韧性显着增强和强度适度增强归因于铁素体含量的增加、更细的铁素体晶粒、更细的珠光体群和更细的层间距。