1 Introduction
2 Experiments and Materials
Chemical compositions (wt. %) | Mechanical properties | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
C | Si | Mn | P | S | Ni | Cr | N | σs (MPa) | σb (MPa) | δ (%) |
< 0.03 | < 1.0 | < 2.0 | < 0.045 | < 0.03 | 6‒8 | 16‒18 | < 0.2 | > 350 | > 700 | > 40 |
Specimen | Welding power (kW) | Welding speed (m/min) | Defocus distance (mm) |
---|---|---|---|
0.8+1.5-N | 2.5 | 2.1 | 0 |
1.5+0.8-P | 2.9 | 1.5 | − 1.2 |
3 Experimental Results
3.1 Microstructure and Tensile Performance
3.2 Fatigue Resistance
Specimen | Fatigue limit P50 | Fatigue limit P99.9 | ||
---|---|---|---|---|
Load (kN) | Normalized load (N/mm) | Load (kN) | Normalized load (N/mm) | |
0.8+1.5-N | 3.47 | 86.8 | 2.63 | 65.8 |
1.5+0.8-P | 4.34 | 108.5 | 3.76 | 94 |
3.3 Fatigue Failure Behavior
3.4 Stress Simulation Analysis
Specimen | P50 (kN) | Upper plate σMises | Lower plate σMises |
---|---|---|---|
0.8+1.5-N | 3.47 | 387 | 326 |
1.5+0.8-P | 4.34 | 354 | 408 |