【摘要】 不同厚度的10CrN iMnMo低合金高强钢连铸连轧并热处理后,强度变化不大,但冲击韧性值却相差较大.采用金相显微镜和透射电子显微镜等手段对低合金钢10CrN iMnMo轧制态及热处理后的组织和性能进行研究.结果表明,轧制态的低合金钢板材上有大量的纳米级碳化物弥散分布于铁素体基体上,但其组织由于板厚的不同而不同.厚板≥12 mm其组织为铁素体+贝氏体;而薄板的组织为铁素体+贝氏体+马氏体+残余奥氏体.在后续热处理中,厚板的强度降低,而冲击韧性变化很大.薄板的强度变化较厚板小,并且冲击韧性变化不明显,这主要是由于马氏体的存在和碳化物析出强化的作用.更多还原

【Abstract】 The toughness of 10CrNiMnMo steel with different thickness is various after rolling and heat treatment.By means of H-800 Transmission Electron Microscope and optical microscope,the structure and mechanical properties of 10CrNiMnMo steel are investigated respectively.It is concluded that there are a great amount of carbide particles with nanometer size dispersed in the matrix of ferrite in the rolled low alloy steel sheets,and their structures vary with the thickness of steel.The structure of sheets with thickness of more than 12 mm shows F+B,and that of sheets with thickness of 8 mm exhibits F+M+B+retained A.In the subsequential heat treatment,the strength of thick sheets is decreased and the impact toughness is improved a lot.But the strength and impact toughness of thin sheets are changed a little for the existence of martensite and the precipitation hardening of carbides.更多还原