汽车用高强度钢板DP800的疲劳性能研究  

Study on Fatigue Performance of Automotive High-strength DP800 Steel

作　　者：于燕[1] 张小盟[1] 江秋[1] 

机构地区：[1]f长春工业大学先进结构材料省部共建教育部重点实验室,吉林长春130012

出　　处：《热加工工艺》2013年第20期106-108,共3页Hot Working Technology

摘　　要：对1.5 mm厚的800 MPa级国产双相钢板(DP800)进行疲劳试验,并对试验数据进行拟合处理,对疲劳断口进行扫描断口分析。结果表明:在加载频率为8Hz、R=0的高周拉—拉疲劳试验条件下,DP800钢板的疲劳极限是490 MPa,疲劳强度为抗拉强度的0.6125倍。当疲劳加载应力σmax≥510 MPa时,DP800疲劳寿命计算公式为:N=±(739252.7448-1172.3673σmax);当σ0≤σmax≤510 MPa时,疲劳寿命的计算公式为:N=±(16170275.66-31471.976σmax);从DP800的疲劳断口可看到明显疲劳条带,疲劳扩展区具有韧性断裂特征,为韧性断裂,瞬断区为脆性断裂。A series of high cycle fatigue experiments of domestic DP800 steel plate with thickness of 1.5 mm were carried out. The fatigue test data were fit and the microstructure of the steel＇s scanning fatigue fracture was analyzed.The results show that： under the conditions of the loading frequency for 8 Hz and R=0, the fatigue limit of DP800 steel plate is 490 MPa. The fatigue strength is 0.6125 times higher than the tensile strength, that is δ0=0.6125δb; the fitted experience formula obtained by S-N curve is that： when δmax≥510MPa, it is N=＋ （739252.7448-1172.36730δmax）; when δ0 ≤δmax≤510 MPa, it is N=＋ （16170275.66-31471.9760δmax）; there are the obvious fatigue banding in the fatigue fracture, the fatigue crack growth area is ductile fracture and the transient breaking area is brittle fracture.

关 键 词：DP800 S-N拟合 断口扫描 疲劳断裂 

分 类 号：TG113.255[金属学及工艺—物理冶金]