9Cr2Mo轧辊钢强韧化处理工艺研究

Strengthening-Toughening Treatment Process of 9Cr2Mo Roll Steel

使用高铬药芯焊丝对报废的9Cr2Mo轧辊钢进行堆焊修复,对堆焊后的试样进行空冷及200~600℃不同温度回火处理,研究不同回火温度对堆焊层组织、韧性及耐磨性的影响。结果表明,空冷和低温回火范围内(200~400℃),堆焊层为粗大的片状回火马氏体,韧性及耐磨性较低,断口呈明显的脆性断裂特征。焊后中温回火(400~500℃),随着回火温度的升高,堆焊层中粗大的片状马氏体逐渐减少,韧性逐渐改善,耐磨性逐渐提高。当回火温度达到500℃时,堆焊层中粗大的片状回火马氏体消失,基体为细小的板条状回火马氏体与弥散分布的细小颗粒状混合组织,韧性及耐磨性较高,断口出现大量的撕裂韧窝。当回火温度达到600℃时,堆焊层出现尺寸较大的球形组织,韧性及耐磨性降低。

The effect Of tempering temperature on the microstructure, toughness and wear resistance of surfacing welding 9Cr2Mo steel roller was studied. The results show that the cladding layer is mainly characterized by thick flake tempered martensite with poor toughness and wear resistance under air cooling and low tempering temperature （200-300 ℃）. With increasing tempering temperature from 400 ℃ to 500 ℃, the thick flake tempered martensite of the cladding layer reduced, while toughness and wear resistance improved gradually. When the tempering temperature reaches to 500 ℃, the thick flake tempered martensite of cladding layer will disappear, and the microstructure changes to the small plate strips of tempered martensite and dispersion distribution of fine granular mixture structure with higher hardness. When the tempering temperature is 600℃, the cladding layer structure changes to large granular with reduced toughness and wear resistance.