碳素钢中氧含量与氧化物分量的测定及其对应关系的探讨

借助氧氮分析仪的程序升温功能,研究了样品表面裂纹对氧含量测定的影响及碳素钢中氧含量的释放特征,探讨了其中不同氧化物与分解释放温度的对应关系.采用氧氮分析仪的温度维持程序升温模式,测定了碳素钢裂纹样品中的氧含量,对其升温曲线和氧释放曲线进行分析,结果表明:碳素钢中氧的释放峰通常分为低(1800℃以下)、中(1950℃左右...

Determination of oxygen content and oxide component in carbon steel and discuss on their corresponding relationship

With the aid of temperature programming function of oxygen-nitrogen analyzer, the influence of sample surface crack on the determination of oxygen content as well as the release feature of oxygen content in carbon steel were studied. The corresponding relationship between different oxides and decomposition release temperature was discussed. The oxygen content in crack sample of carbon steel was determined by the temperature keep warming program of oxygen-nitrogen analyzer. The warming curve and oxygen release curve was analyzed. The results showed that the release peaks of oxygen in carbon steel usually had three temperature ranges, i.e., low temperature (below 1 800 ℃), medium temperature (around 1 950 ℃) and high temperature (around 2 200 ℃). The existence of cracks only influenced the oxygen content in low temperature zone (below 1 800 ℃), while it had no influence on the oxygen release peak position and intensity (oxygen content) in the zone of medium temperate and high temperature (not less than 1 800 ℃). The reasonable parameters of substep ladder warming program were established in experiments. The oxide components in the surface crack sample and the normal sample with clean surface were determined at the mode of substep ladder warming program. The results showed that the oxygen content at low temperature zone in carbon steel sample was the sum of oxygen in few low temperature oxides and the solid solution oxygen. The sum of oxygen content in the zone of medium temperate and high temperature was not affected by the sample preparation method, the sample state or sample surface quality. The pulse melting decomposition temperature simulation experiments of oxides, which possibly existed in carbon steel, were conducted. The corresponding relationships between oxygen component and various oxides were discussed. The results showed that the decomposition temperatures of FeO, MnO, NiO and Fe₂O₃ in carbon steel were all below 1 800 ℃. After the oxygen release peak below 1 800 ℃ was deducted by sufstep ladder warming program, the oxygen content, which was corresponding to the release peaks in the zone of medium temperate and high temperature, was directly related to the contents of various oxide inclusions (such as SiO₂, Al₂O₃, CaO and their complex compounds) in the steel.