热处理对含锰6％的中锰球墨铸铁组织及性能的影响

采取不同的淬火（800℃，900℃，1000℃）和回火（200℃，400℃，600℃）热处理工艺，对含锰6％的中锰球墨铸铁组织和力学性能进行了研究．结果表明：中锰球墨铸铁的合理热处理工艺为在900℃奥氏体化保温2h水淬，在200℃回火2h水淬．淬火后的组织为大量的马氏体＋贝氏体＋残余奥氏体＋球状石墨，淬火和回火后的组织为回火马氏体＋贝氏体＋少量残余奥氏体＋碳化物＋球状石墨．热处理后试样的硬度下降，冲击韧性提高，耐磨性下降．淬火温度对试样的硬度、冲击韧性和耐磨性影响较大，回火温度对试样的硬度、冲击韧性和耐磨性影响较小．

Effect of Heat Treatment on Microstructure and the Mechanical Properties of Medium Manganese Nodular Cast Iron with 6%Mn

The influences of quenching （800 ℃ ,900 ℃ ,1000 ℃ ） and tempering （200 ℃ ,400 ℃ ,600 ℃ ） processes on mierostructure and the mechanical properties of Medium Manganese Nodular Cast Iron with 6% Mn were studied. The results show that the optimized heat treatment of Nodular Cast Iron is austenitie treated at 900 ℃ for 2 h followed by water quenching, and then tempered at 200 ℃ for 2 h before water quenching. Quenching microstrueture of Nodular Cast Iron is major martensite ＋ bainite ＋ retained austenite ＋ spheroidal graphite. Microstructure of Nodular Cast Iron after quenching and tempering is tempered martensite ＋ bainite ＋ a small amount of retained austenite ＋ carbide ＋ spheroidal graphite. After heat treatment, hardness of samples decreased, impact toughness improved, wear resistance decreased. Quenching temperature has greater impact on the mechanical properties than tempering temperature.