1. Introduction

The crankshaft is a crucial part of the automobile engine, responsible for power output. This article focuses on the wet sand casting process of automotive crankshafts, analyzing the casting process, defects, and control methods to improve casting quality and efficiency.

Main Points	Details
Significance of Crankshaft	Key component for power output in automotive engines, affected by various factors
Research Focus	Wet sand casting process, defect analysis, and control strategies

2. Materials for Automotive Crankshafts

The choice of material for the crankshaft is crucial, considering both mechanical properties and cost.

Material	Properties	Application in Crankshaft
Ductile Iron (QT900 – 2)	Good mechanical properties, economic, high resistance to torsion and bending, excellent impact resistance	Widely used in automotive crankshaft production

3. Wet Sand Casting Process for Ductile Iron Crankshafts

The wet sand casting process for ductile iron crankshafts mainly includes sand mold preparation and pouring.

Process Steps	Details
Sand Mold Preparation	Composition: 5% new sand and the rest old sand. Aim: To create a suitable mold for casting the crankshaft
Pouring Process	Scheme: Sequential solidification (as shown in Fig. 1). Benefit: Suitable for mass production and effective defect control

4. Defects and Control in Wet Sand Casting of Ductile Iron Crankshafts

Various defects can occur during the casting process, and effective control measures are essential.

Defect Type	Cause	Control Measures
Sand Inclusion	Factors like spheroidizing agent and sand. Impact: Complicates post – casting cleaning. Solutions: Add a filter at the pouring end; control sand quality in secondary pouring
Porosity	Nitrogen bubbles trapped during solidification. Effect: Reduces mechanical strength. Prevention: Use low – nitrogen raw materials; add vents at thick – walled parts
Shrinkage and Porosity	Caused by heat transfer in the sand mold. Solution: Place chills outside the hot spot; improve casting process parameters

5. Conclusion

Wet sand casting of ductile iron crankshafts simplifies production, reduces costs, and enables effective defect control.

Advantages	Details
Process Simplification	Reduces production steps compared to traditional methods
Cost Reduction	Lowers production costs
Defect Control	Allows for better control and elimination of casting defects

In summary, the wet sand casting process for automotive crankshafts offers a viable solution for efficient and high – quality production.