초록 ▼

There is provided a high-pressure fuel pipe for diesel engines, which is excellent in inner-pressure fatigue resistant property, vibrational fatigue resistant property, cavitation-resistant property, seat surface crack resistant property, and bending shape stability, and capable of thinning and ligh

There is provided a high-pressure fuel pipe for diesel engines, which is excellent in inner-pressure fatigue resistant property, vibrational fatigue resistant property, cavitation-resistant property, seat surface crack resistant property, and bending shape stability, and capable of thinning and lightening. A high-pressure fuel pipe for diesel engines, composed of a low alloy transformation inducing plastic type strength steel containing residual austenite of 5 to 40 wt %, and wherein an inner surface of a flow passage has a crack depth of 20 μm or less, and plastic working is applied to an inner surface of a flow passage.

대표청구항 ▼

1. A high-pressure fuel pipe for diesel engines, composed of a low alloy transformation inducing plastic type strength steel containing residual austenite of 5 to 40 wt %. 2. The high-pressure fuel pipe for diesel engines, according to claim 1, wherein an inner surface of a flow passage has a crack

1. A high-pressure fuel pipe for diesel engines, composed of a low alloy transformation inducing plastic type strength steel containing residual austenite of 5 to 40 wt %. 2. The high-pressure fuel pipe for diesel engines, according to claim 1, wherein an inner surface of a flow passage has a crack depth of 20 μm or less. 3. The high-pressure fuel pipe for diesel engines, according to claim 2, wherein plastaic working is applied to an inner surface of a flow passage. 4. The high-pressure fuel pipe for diesel engines, according to claim 3, wherein the plastic working comprises autofrettage working. 5. The high-pressure fuel pipe for diesel engines, according to claim 1, wherein the low alloy transformation inducing plastic type strength steel comprises ferrite (αf)+bainite (αb)+γR composite structure steel [TRIP type Dual-Phase steel, TDP steel], and bainitic ferrite (αbf)+γR steel [TRIP tpe bainite steel, TB steel], which are improved in press molding quality by utilization of strain inducing transformation (TRIP) of residual austenite (γR).