Forgings of Nozzle Holder Body for Common Rail System

1. Process Specifications

1.1 It is recommended to use vertical closed-die forging process to ensure a streamlined distribution along the outer shape of the forged part.

1.2 The general process flow includes material cutting, weight distribution, shot blasting, pre-lubrication, heating, forging, heat treatment, surface cleaning, magnetic particle inspection, etc.

1.3 Single-station forging is preferable for forming. 1.4 Materials should be selected from 45# steel, 20CrMo, 42CrMo steel, and other similar materials.

1.5 It is advisable to use sawing machine for material cutting to remove head and tail portions.

1.6 Hot-rolled peeled bar stock is preferred.

1.7 To ensure the product is fully filled and improve die lifespan, it is recommended to use multi-stage weight sorting machines to classify defective materials by quality.

1.8 Defective materials should undergo shot blasting pretreatment. The selection of shot blasting equipment, such as appropriate diameter of shots (around Φ1.0mm to Φ1.5mm), should consider factors such as surface requirements of billets, quantity of shots per cycle, shot blasting time, and shot lifespan.

1.9 The preheating temperature for defective materials should be within 120℃ to 180℃.

1.10 Pre-coating graphite concentration should be determined based on graphite type, surface quality of forgings, heating temperature, and duration.

1.11 Graphite should be uniformly sprayed on the surface of defective materials without any clumping.

1.12 Graphite should be able to withstand temperatures around 1000℃ ±40℃.

1.13 Medium-frequency induction heating furnaces are recommended for heating equipment.

1.14 The heating time for defective materials can be determined based on the heating equipment, billet size, and production pace, aiming to achieve uniform temperature for forging initiation.

1.15 The selection of heating temperature for defective materials should contribute to improving material formability and obtaining good post-forging structure and surface quality.

1. Forging

2.1 The selection of parting surfaces for forgings should facilitate mold removal, metal filling in the cavity, and mold processing.

2.2 Numerical simulation analysis should be used to calculate deformation force and blocking force during the forming process.

2.3 The preheating temperature range for molds is generally between 120℃ and 250℃, with a minimum preheating time of 30 minutes. The mold temperature should not exceed 400℃ during the production process.