PL EN
Microstructure and Hardness of Cold Forged 42CrMo4 Steel Hollow Component with the Outer Flange
 
Więcej
Ukryj
1
Department of Materials Engineering, Mechanical Engineering Faculty, Lublin University of Technology, Poland, Nadbystrzycka 36, 20-618, Lublin, Poland
2
Department of Metal Forming Technologies, Mechanical Engineering Faculty, Lublin University of Technology, Nadbystrzycka 36, 20-618 Lublin, Poland
AUTOR DO KORESPONDENCJI
Mirosław Szala   

Department of Materials Engineering, Mechanical Engineering Faculty, Lublin University of Technology, Poland, Nadbystrzycka 36, 20-618, Lublin, Poland
 
Adv. Sci. Technol. Res. J. 2022; 16(4):201–210
 
SŁOWA KLUCZOWE
DZIEDZINY
 
STRESZCZENIE
For decades, steel has been a crucial structural material. Mainly low-alloy steel grade ISO 42CrMo4 is utilized for manufacturing forgings. This paper investigates the microstructure and hardness development of the 42CrMo4 steel hollow component with an outer flange. The component has been formed via cold forging in combination with extrusion and upsetting technologies. Prior to forming, the workpiece was annealed to obtain hardness at the level of 181±9 HV0.3. The FEM analysis reveals the areas that undergo higher stress and strain. The flow lines macrostructure and microstructure of hollow parts were investigated using light optical microscopy (LOM) and scanning electron microscopy (SEM) equipped with EDS. Vickers hardness allows identifying the work hardening of the crucial element areas. The microstructure consists of ferrite matrix and semi-globular carbides. Laboratory studies confirm appropriate flow lines arrangement, which corresponds well to those shown by FEM computer simulations. The highest hardness at the level of 293±7 HV0.3 was identified in the flange area, where the material shows a higher distribution of effective strain revealed by FEM. Cold metal forming results in work-hardening of the steel. The work hardening ranges up to 1.62 of the initial 42CrMo4 steel hardness. The metal forming process did not affect the microstructural uniformity of the flanged hollow part. The final outer flange component presents high quality and is free from plastic deformation nonuniformities.