Non-destructive measurement of microstructure and tensile strength in varying thickness commercial DP steel strip using an EM sensor
Non-destructive measurement of microstructure and tensile strength in varying thickness commercial DP steel strip using an EM sensor
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DOI：
10.1016/j.jmmm.2018.10.099
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发表时间：
2019-03
影响因子：
2.7
通讯作者：
M. Aghadavoudi-Jolfaei;J. Shen;A. Smith;Lei Zhou;C. Davis
中科院分区：
文献类型：
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作者：
M. Aghadavoudi-Jolfaei;J. Shen;A. Smith;Lei Zhou;C. Davis
人们希望能够无损地评估带钢的组织特征和/或力学性能。在COMSOL多物理软件中建立了电磁传感器-样品有限元模型，用于确定任意厚度的商用双相钢板的低磁场相对磁导率与组织(相平衡和晶粒度)以及抗拉强度之间的关系。用厚度为1~4 mm的DP钢板验证了厚度对传感器信号影响的模型。结果表明，DP钢的相对磁导率强烈依赖于相平衡(铁素体和马氏体相的比例)，铁素体含量越高，相对磁导率越高。此外，铁氧体颗粒尺寸的变化也会影响相对磁导率(颗粒尺寸的增大会增加相对磁导率)，从而影响EM传感器信号，这对于铁氧体含量较高的DP等级更为显著。这两种组织特征都会影响抗拉强度(随着铁素体含量的增加和晶粒度的增大而降低)，从而导致相对渗透率与抗拉强度之间有很好的相关性。将相对渗透率-显微组织-抗拉强度调查的结果和考虑带钢厚度的有限元模型结合起来，可以根据EM传感器测量的不同厚度的商业DP钢板的抗拉强度进行预测，并对该方法进行了测试。
It is desirable to be able to non-destructively evaluate the microstructural features and/or mechanical properties of steel strip. An electromagnetic sensor – sample FE model, developed in COMSOL multi-physics software, has been developed to determine the relationship between the low magnetic field relative permeability and microstructure (phase balance and grain size), and hence tensile strength, for commercial dual phase (DP) steel sheets of any thickness. The model for the effect of thickness on the sensor signal has been validated using DP steel sheets of 1 to 4 mm. It was found that the relative permeability is strongly dependent on the phase balance (fraction of ferrite and martensite) in the DP steels with an increasing relative permeability being seen for a higher fraction of ferrite. In addition, changes in the ferrite grain size also affect the relative permeability (increase in grain size increases relative permeability) and hence EM sensor signal, this being more significant for the higher ferrite content DP grades. Both these microstructural features affect the tensile strength (which decreases with an increase in ferrite fraction and increase in grain size), which results in a good correlation between the relative permeability and tensile strength. The results from the relative permeability – microstructure – tensile strength investigation and FE model to account for strip thickness have been combined to allow the prediction of tensile strength from EM sensor measurements on as-received commercial DP steel sheets of varying thickness and the approach has been tested.