摘要
对两种不同晶粒度的低合金高强钢(WCF-62)的试样在常温下获得均匀预应变后(0～20%),在-125 ℃下对预应变和未预应变的试样进行了四点弯曲试验,测量了宏观和微观力学参数,以及断口参数.并结合有限元计算所得的不同预应变条件下的缺口前端的应力应变场分布,分析了预应变对不同晶粒度低合金高强钢缺口试样断裂行为的影响.结果表明:粗晶和细晶材料在室温预应变3%后,缺口韧性有明显的降低,但是随预应变进一步增加,缺口韧性基本保持不变.原因是预应变3%后两种材料解理断裂都转变为起裂控制.
Four point bending (4PB) tests of the specimens of two kinds of high-strength low-alloy steel (WCF-62) with different graininess and different level of pre-strain are carried out at -125 ℃. Macro- and microscopic mechanical parameters and those of fracture surface are measured. In association with the FEM calculation results of the stress and strain distributions around the notch tip of specimens with different pre-strains, the influence of the pre-strain on fracture behavior of specimen is analyzed. It is discovered that the specimen shows an appreciable decrease in notch toughness after applying 3% tensile pre-strain at room temperature. The further pre-strain up to 20% gives little effect. This is because that the cleavage-controlling factors of two materials have be converted into initiation of crack nucleus since the 3% tensile pre-strain being applied.
出处
《甘肃工业大学学报》
北大核心
2002年第1期1-6,共6页
Journal of Gansu University of Technology
基金
国家自然科学基金(59871015)
