一种新型高强韧性H型钢的试验研究

Experimental Study on A New Type of High Strength and Toughness H Beam

关键词:  钢结构  H型钢  硼  显微组织  力学性能

Key words:  steel structure  H beam  boron  microstructure  mechanical property

摘要:

为了解决传统低合金高强度H型钢低温冲击韧性较低的问题，从成分设计入手，首次尝试将硼加入到此类钢中，研究了硼对钢材显微组织和力学性能的影响.结果表明：虽然含硼钢的强度和塑性增加不大，但其冲击韧性却大幅提高，特别是低温冲击韧性尤为显著.加硼之后，Nb（C，N）变得细小且弥散分布，显微组织在一定程度上得到细化，而且材料的脆性断裂受到抑制，从而使韧脆转变温度显著降低.

Abstract:

In order to solve the problem that low temperature impact toughness of traditional high strength low alloy H beam is lower, from taking account of composition design, boron was added into this type of steel for the first time, and the effect of boron on microstructure and mechanical properties was investigated. The results show that compared with non boron steel the strength and the plasticity of boron contained steel are increased slightly, moreover the impact toughness is improved greatly, especially at low temperature. The microstructure is refined to a certain extent because of the smaller and evenly distributed Nb（C,N）precipitates and also the brittle fracture of the materials is restrained by boron addition, so that the ductile brittle transition temperature is significantly reduced.