过氧化氢-草酸预处理脉冲红外法测定轮轴钢中痕量氧

Determination of trace oxygen in wheel axle steel by pulse infrared method after pretreatment with oxalic acid-hydrogen peroxide

研究了脉冲红外法测定钢中痕量氧的试样前处理条件和仪器分析条件。当光洁度为Ra3．2μm以上，直径为4～5mm，长度为5～7mm的圆棒试样用乙醚清洗后，再用过氧化氢-草酸溶液浸泡清洗，水冲洗干净，置于丙酮中再清洗两次，可有效去除表面氧化膜，测得试样中氧含量的值比未经过氧化氢-草酸溶液清洗的要低，与用麂皮抛光表面方法的测定值相当。在优化的仪器分析条件下，用本法成功地测定了轮轴钢中痕量氧，相对标准偏差为3．5％～11．2％，标样的测定值与认定值相符。

The sample pretreatment and analytical conditions of instrument for determining trace oxygen in steel by pulse infrared method were studied. The smoothness of round bar sample was above Ra 3.2 μm with diameter of 4--5 mm and length of 5--7 mm. After being cleaned with ether, the sample was immersed into hydrogen peroxide-oxalic acid solution, and then washed with water. Subsequently, the round bar was washed for twice with acetone to remove oxide film on surface. The measuring result of oxygen content in sample was lower than that without cleaning by hydrogen peroxide-oxalic acid solution, and equivalent to that of chamois leather polishing method. Under optimized analytical conditions of instrument, the content of trace oxygen in wheel axle steel was successfully determined by this method, with RSD of 3.5 % -- 11.2 %. The measuring results of standard sample were in good agreement with the certified values.