A Method to Determine Lankford Coefficients (R-Values) for Ultra High Strength Low Alloy (Uhsla) Steels
A Method to Determine Lankford Coefficients (R-Values) for Ultra High Strength Low Alloy (Uhsla) Steels
复制标题
确定超高强度低合金 (Uhsla) 钢兰克福德系数（R 值）的方法
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
M. Gösling
中科院分区：
文献类型：
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作者：
M. Gösling
对于超高强度低合金钢(UHSLAS)，由于稳定应变比的测量通常是不可能的，因此很难确定朗克福德参数。本文介绍了一种测定超高强度低合金钢的兰克福德系数的方法。该方法基于理论材料模型和材料数据库的经验相结合。用Hill‘48屈服条件计算了Lankford系数作为屈服应力的函数。基于Bilstein材料数据库的经验模型被用来预测各向异性。试验结果作为经验模型的输入参数。该方法首先使用拉伸试验的数据进行检验。将预测的兰克福系数与实测的兰克福系数进行比较。进一步，将该方法应用于屈服应力大于900 Mpa的低合金钢。对于这些材料，兰克福德系数不能通过拉伸试验来测量。将预测的Lankford系数应用于静力试验的数值模拟，并与试验结果进行了比较。总之，可以说，本文提出的方法适用于在不可能直接测量的情况下预测兰克福德系数。
For Ultra High Strength Low Alloy Steels (UHSLAS) it is difficult to determine Lankford parameters, since the measurement of a stable strain ratio is often not possible. This report presents a method for determining Lankford coefficients for UHSLA Steels. The method is based on a combination of a theoretical material model and on experiences from a material data base. The Hill’48 yield condition is used to calculate the Lankford coefficients as a function of the yield stress. An empirical model based on the BILSTEIN material data base is used to predict the anisotropy. The result from earing test is used as an input parameter for the empirical model. The method is first checked using data from tensile tests. The predicted Lankford coefficients are compared with measured Lankford coefficients. In a further step, this method is applied to low alloyed steels with a yield stress of more than 900 MPa. For these materials the Lankford coefficients could not be measured by tensile tests. Predicted Lankford coefficients are used in the numerical simulation of earing test and compared with experimental results. In summary, it can be stated that the method presented here is suitable for predicting Lankford coefficients in case of an impossible direct measurement.