Abstract：In order to study the effect of B content on the microstructure and mechanical properties of FB2 steel,five groups of FB2 steels with different B contents were immersed and corroded for 90 s with Veller's reagent (1 g picric acid,5 mL hydrochloric acid and 100 mL anhydrous ethanol),and the morphology was observed and analyzed. Then,The M23C6 carbide in the matrix was observed and analyzed by SEM-EDS,and the size of precipitated phase was analyzed by Image-Pro Plus software. Then,the AG-XPLUS 100 kN universal testing machine produced by Shimadzu Manufacturing Institute of Japan was used to conduct room temperature tensile test and room temperature impact test on 5 groups of FB2 steel with different B content. Finally,the microstructure and mechanical properties of five groups of FB2 steels with different B contents were analyzed. The results show that the B element in FB2 steel can inhibit the growth coarsening of M23C6 type carbides,but B element is easy to form BN inclusions with N element. With the increase of B content,the average size of M23C6 carbide decreases,and the unit number and average size of BN inclusions show an increasing trend. The tensile properties of FB2 steel at room temperature increase first and then decrease with the increase of B content,and the tensile properties of FB2 steel reach the maximum at 0.010% B mass percent. When the mass percent of B increases from 0 to 0.010%,the tensile properties of FB2 steel increase at room temperature because the addition of B prevents the coarsening of M23C6 carbide,and thus improves the strength of FB2 steel. When the mass percent of B increases from 0.010% to 0.030%,the tensile property of FB2 steel decreases at room temperature because the BN inclusion formed by the combination of B element and N element causes stress concentration,and the large size BN inclusions induce the formation of holes,which reduces the properties of FB2 steel. The impact energy of FB2 steel decreases with the increase of B content,and plummets when the B mass percent is 0.020% and 0.030%,which is caused by the unit number of BN inclusions,the increase of average diameter,and the precipitation of large size BN and debris.
陶学儒, 耿鑫, 姜周华, 李扬, 彭雷朕. 硼元素对FB2钢组织和力学性能的影响[J]. 钢铁, 2022, 57(10): 158-169.
TAO Xue-ru, GENG Xin, JIANG Zhou-hua, LI Yang, PENG Lei-zhen. Effect of element B on microstructure and mechanical properties of FB2 steel[J]. Iron and Steel, 2022, 57(10): 158-169.
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