【摘要】 通过金相、扫描及系列冲击等试验方法研究了洁净度对38CrMoAl钢韧脆转变的影响。结果表明,低洁净度电炉钢与高洁净度双真空钢的韧脆转变温度都是-60℃。但是,在整个连续冲击试验温度范围内,DV钢的冲击韧性均高于EF钢。在连续冲击的上平台区,前者比后者高25 J左右,随着温度下降两者的差距随之降低,在上下平台之间区域内,前者比后者高5~10 J,随着温度继续下降进入到下平台区域,两者差距越来越小,直至差距为零。低的S、P元素含量,较少的MnS、AlN夹杂物是洁净度较高的DV钢韧性较好的主要原因。更多还原

【Abstract】 The effect of cleanliness on the ductile-brittle transition of 38CrMoAl steel was studied by optical microscopy,scanning electron microscopy and series impact test. The results show that for the low purity of electric furnace steel and the high purity of double vacuum steel, the ductile-brittle transition temperature is both –60 °C. Nevertheless, in the entire scope of series impact test, toughness of DV(double vacuum) specimens is higher than that of EF(electric furnace)specimens. For the upper platform of ductile-brittle transition, the toughness of DV specimens is about 25 J higher than that of EF specimens, and with decreasing temperature, the gap is shrunk. Between the upper platform and the lower platform, the former is about 5–10 J higher than the latter. In the scope of the lower platform, the gap become less and less.The lower S, P elements contents and the less amounts of MnS and AlN are the main reason for that the toughness of DV steel is higher than that of EF steel.更多还原