以高硼低碳合金为对象,研究经1 000℃×1.5 h+240℃×3.0 h的淬火、回火热处理后其组织及性能的变化规律,分析其强韧机理。结果表明,经淬火回火处理后,钢中出现了板条马氏体、Fe2B和极少量的残余奥氏体组织;高温淬火处理使少量Fe2B溶解,改善硼化物形态,增强板条马氏体基体的连续性,弱化Fe2B的脆性;高温回火能消除试验钢淬火时产生的残留应力,提高材料强度、韧性和疲劳性能。 Taking high boron and low carbon alloy as object, the change regularity of microstructure and properties after quenching and tempering at 1000 ℃ × 1.5 h + 240 ℃ × 3.0 h was studied, and its toughness mechanism was analyzed. The results show that after quenching and tempering, lath martensite, Fe2B and a small amount of residual austenite appear in the steel. High temperature quenching dissolves a small amount of Fe2B to improve the morphology of the boride and enhance lath martensite The continuity of the matrix weakens the brittleness of Fe2B. High-temperature tempering can eliminate the residual stress during quenching of the test steel and improve the strength, toughness and fatigue properties of the material.