摘要
为了提高SA516Gr70结构钢的力学性能,通过添加稀土元素RE(质量分数为0.000%,0.006%和0.012%)的方式来改善其力学强度。通过实验测试的手段比较了3组不同条件下制得的钢材试样的拉伸与冲击性能的差异性。研究结果表明:试样中主要存在铁素体与珠光体两种成分。添加RE后,中心区域形成了更多的等轴晶组织,减小了SA516Gr70钢的晶粒尺寸、提升了力学强度。RE类夹杂物可以成为α-Fe相的异质形核点,制得由更细小晶粒组成的SA516Gr70钢。在钢材内加入RE能够使SA516Gr70钢获得更高拉伸强度和抗冲击能力。RE添加量增加至0.012%时,钢材的拉伸强度与屈服强度分别增大至592与516 MPa,-40℃环境中的冲击吸收功提高了8.3%,处于-60℃下的冲击吸收功提高了13.8%。随着RE添加量的增加,断口韧窝的深度也显著提高,表现为明显的韧性断裂,产生明显的塑性变形。
In order to improve the mechanical properties of structural steel SA516 Gr70, its mechanical strength was improved by adding rare earth element RE(the mass fractions of 0%, 0.006% and 0.012%), and the differences in tensile and impact properties of steel specimens prepared under three groups of different conditions were compared by means of experimental test. The results show that the ferrite and pearlite are the main components in the samples. After RE is added, more equiaxed grain structures are formed in the central region, which reduces the grain size and improves the mechanical strength of SA516 Gr70 steel, and RE-type inclusions can become heterogeneous nucleation points of α-Fe phase to produce SA516 Gr70 steel composed of finer grains. In addition, adding RE into steel can make SA516 Gr70 steel obtain higher tensile strength and impact resistance. When the amount of RE is added to 0.012%, the tensile strength and yield strength of steel increase to 592 and 516 MPa respectively, and the impact absorption energies increase by 8.3% at-40 ℃ and 13.8% at-60 ℃. With the increasing of RE, the depth of fracture dimple also increases significantly, which shows obvious ductile fracture to result in obvious plastic deformation.
作者
吴立凡
李涛
Wu Lifan;Li Tao(Department of Metallurgy and Chemical Industry,Baotou Iron&Steel Polytechnic,Baotou 014010,China;School of Materials and Metallurgy,Inner Mongolia University of Science and Technology,Baotou 014010,China)
出处
《锻压技术》
CAS
CSCD
北大核心
2021年第11期255-259,共5页
Forging & Stamping Technology
基金
内蒙古自然科学基金资助项目(2019MS05054)。