Ductile iron can be widely used in crankshafts after being quenched by medium frequency induction quenching equipment.

The crankshaft is an important part of the engine. Its rotation is the power source of the engine and the entire mechanical system. Therefore, its application range is very wide. The commonly used material for crankshafts is carbon structural steel, but research has found that ductile iron can also be used as an important material for crankshafts after being quenched by medium-frequency induction quenching equipment.

As a material for manufacturing crankshafts, high fatigue strength (bending, torsion), wear resistance and rigidity are required in terms of performance. From the analysis of the material properties of induction quenched ductile iron, it can be seen that induction quenched ductile iron is an ideal engineering material for manufacturing crankshafts. It is generally believed that if the tensile strength of ductile iron is 800MPa and still cannot meet the requirements, induction hardened ductile iron can be used instead of forged steel. Volvo car crankshafts, some Ford Motor Company engine crankshafts, and some high-power diesel engine crankshafts are all made of induction-hardened ductile iron.

Ductile iron crankshafts are favored by designers due to their low material and processing costs, and are widely used in cars and low-load vehicles. However, they are limited by the fact that the bending fatigue strength of ordinary ductile iron is lower than that of forged steel. It is especially difficult to meet performance requirements on heavy-duty engine vehicles. The service conditions of engine crankshafts are very complex and harsh. A large number of actual crankshaft failure accident statistics show that bending and torsional fatigue fracture are the main damage forms of crankshafts, especially bending fatigue strength failure is more common. Induction hardened ductile iron material has high bending fatigue strength and overall strength. At the same time, due to the presence of austenite structure in its matrix, it has a significant work hardening effect. After fillet rolling, martensitic transformation occurs, forming a very high The residual compressive stress increases the fatigue strength of the crankshaft.

Therefore, the ductile iron crankshaft has great potential to replace some forged steel crankshafts. At the same time, the induction quenched ductile iron crankshaft can reduce its own weight by about 10% compared with forged steel, and the manufacturing cost can also be greatly reduced. As a new crankshaft material, it has Very good application promotion prospects.

Domestically, Nanjing University of Science and Technology conducted tests on using induction-hardened ductile iron to manufacture the 368Q crankshaft for passenger cars. After bench testing, full-speed and full-load reliability testing and 30,000 kilometers of road testing, it has passed the ministerial appraisal. The safety factor is 1.7, which is higher than the safety factor of imported forged steel crankshafts (1.6). The main journal and connecting rod journal are worn. The quantity is also far below the standards of the Mechanical Department. The conventional mechanical properties, fatigue strength, wear resistance strength, workmanship, safety and reliability of the induction quenched ductile iron crankshaft all meet the design and use requirements. The economic benefits are obvious, the workmanship, safety and reliability, etc. all meet the design and use requirements. It is economical. The benefits are obvious. According to cost estimation, imported forged steel crankshaft: domestic 40Cr forged steel crankshaft: induction hardened ductile iron crankshaft = 2.7:1.84:1.

Induction quenching ductile iron material replaces forged steel to make crankshafts. Compared with its static strength and bending fatigue strength, induction quenching ductile iron crankshafts can meet the service conditions of high-power supercharged diesel engines, and they have significant advantages in cost. Using induction quenching The production of high-power supercharged diesel engine crankshafts from ductile iron is a project with significant technical and economic benefits, which should attract the attention of the domestic automobile industry.

Ductile iron is widely used in crankshaft manufacturing due to its excellent physical and mechanical properties. With the development of ductile iron smelting and alloying technology and induction quenching ductile iron, the performance of ductile iron has been continuously improved. In order to save costs, using ductile iron instead of forged steel to produce engine crankshafts is a development trend in crankshaft production.

In summary, due to its unique advantages, using ductile iron to produce crankshafts is the general trend. It can greatly reduce your production costs and bring you greater economic benefits.