球墨铸铁金相定量分析方法探讨

Discussion on the Quantitative Metallographic Analysis of Nodular Iron

比较了《球墨铸铁金相检验》标准GB/T 9441-1988与GB/T 9441-2009中关于石墨球化率、石墨大小及珠光体评价方法的异同,探讨了利用图像分析软件对球墨铸铁球化率、石墨大小及珠光体含量进行定量分析的准确性,指出:(1)目前软件法评定石墨球化率的应用具有局限性,球化率不高时检测结果与实际值偏差较大,建议依据GB/T 9441-2009对图像处理软件球化率定量分析的数学模型进行更新;(2)为保证分析准确性,球化率、石墨大小的评定必需进行前处理;(3)软件法无法直接定量评定球墨铸铁中的珠光体含量,但可以采用"两步法"实现球墨铸铁珠光体含量的定量评定。

The differences and similarities between GB/T 9441-1988 and GB/T 9441-2009 《Metallographic Inspection》Standard about evaluation of nodularity rate,graphite size and pearlite content were compared. The veracity of using image analysis system to conduct nodularity,graphite size and pearlite content quantitative analysis of nodular iron was discussed and it was pointed out：（1）At present,the application of software assessing nodularity was limited. When the nodularity was lower,the inspection result was very different to the real value. It＇s suggested to renew the mathematic model of nodularity quantitative analysis image treating software according to China Standard GB/T 9441-2009.（2）In order to ensure analysis veracity of nodularity and graphite size assessing,the pretreatment was indispensable.（3）Since software method couldn＇t to be used to directly quantitatively assess pearlite content of nodular iron,it＇s possible to use＂two-step method＂to realize pearlite content quantitative assessing of nodular iron.