应用极值分析评估帘线钢大尺寸夹杂物分布

基于定量金相检测的大颗粒夹杂物的尺寸，应用 ASTME2283中极值分析的标准化方法（最大似然估计法）对帘线钢冶炼过程所取试样中夹杂物尺寸分布进行了统计分析，并采用 SEM/XPS对大尺寸夹杂物进行了成分检测。分析结果表明：在逆程周期为 1000的检测条件下，通过极值分析方法可计算出试样中相对应 99.90%概率的最大夹杂物尺寸，客观描述了帘线钢中夹杂物尺寸分布特征；某一视场或不同视场内发现不同成分类型的大尺寸夹杂物： CaO-SiO2类和 SiO2-MnO类两类夹杂物具有不同的尺寸分布规律；软吹 40min时 SiO2-MnO类夹杂物出现大尺寸概率明显小于 CaO-SiO2类夹杂物，说明大尺寸夹杂物主要为 CaO-SiO2类夹杂物。

Sizedistribution of large size inclusions in tire cord stee lby extreme value analysis

Based on the quantitative metallographic examination of the large inclusion size，the statistical analysis of inclusion size distributions in the samples taken from the tire cord steel production process was carried out by using the extrem evalue analysis standard method of ASTM E2283（the maximum likelihood method），and the large size inclusion compositions were detected by SEM/XPS. The analysis results indicated that under the detection condition of return period equal to 1 000，the maximum inclusion size corresponding to the probability of 99.90% could be calculated，thus the distribution features of inclusions size in tire cord steel could be objectively described. Two types of large size inclu-sions，which were CaO-SiO₂ type and SiO₂-MnO type，were found in acertainor different metallographic microscope fields of view，and these two different type inclusions had different size distribution regulation. The probability of large size of SiO₂-MnO type inclusions was significantly smaller than that of CaO-SiO₂ type inclusions when the soft blowing time was 40 min，which illustrated that the larger size inclusions were mainly CaO-SiO₂ type.