Influence of tempering conditions on microstructure and mechanical properties of a newly designed low alloy ultrahigh strength steel
Influence of tempering conditions on microstructure and mechanical properties of a newly designed low alloy ultrahigh strength steel
复制标题
回火条件对新设计的低合金超高强度钢显微组织和力学性能的影响
DOI：
10.4149/km_2018_2_89
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发表时间：
2018
影响因子：
0.7
通讯作者：
Chen G
中科院分区：
文献类型：
--
作者：
Feng Y Y;Xu C;Sun Y L;Bu C C;Cao Y D;Chen G
本研究设计了一种低合金高强钢，并对其在不同回火条件下的力学性能和显微组织进行了分析。该钢的组织为板条马氏体，在特定条件下，其显微组织中存在高密度位错和大量碳化物。随着回火温度的升高，材料的强度和硬度降低，而韧性变化不一。在200 ℃回火时，获得了最佳的强度和韧性组合。延长保温时间可提高强度，但降低韧性。回火马氏体脆化发生在300-400 ℃。断口分析表明，材料在100 ℃时以准解理方式断裂，200-400 ℃时以准解理和微孔聚结方式断裂，500 ℃时以沿晶断裂。低合金高强钢，回火温度，保温时间，力学性能，显微组织
In this research, we designed one low alloy ultrahigh strength steel and performed an analysis of the mechanical properties and microstructures at different tempering conditions. The structure of the steel is lath martensite with a high density of dislocations combined with many carbides precipitated in the microstructures at specific conditions. Strength and hardness of the material were found to decrease, while toughness varied differently as the tempering temperature increased. The best combination of strength and toughness was obtained when tempered at 200◦C. Prolonging the holding time led to higher strength but lowered toughness. Tempered martensite embrittlement occurred at 300–400◦C. The ruptured surface indicated that the material had fractured in a quasi-cleavage manner at 100◦C, quasi-cleavage and microvoid coalescence fracture occurred at 200–400◦C, intergranular fracture at 500◦C. K e y w o r d s: low alloy ultrahigh strength steel, tempering temperature, holding time, mechanical properties, microstructure