Effect of shot peening on the residual stress and mechanical behaviour of low-temperature and high-temperature annealed martensitic gear steel 18CrNiMo7-6
Paper in proceedings, 2017

A martensitic gear steel (18CrNiMo7-6) was annealed at 180 °C for 2h and at ∼ 750 °C for 1h to design two different starting microstructures for shot peening. One maintains the original as-transformed martensite while the other contains irregular-shaped sorbite together with ferrite. These two materials were shot peened using two different peening conditions. The softer sorbite + ferrite microstructure was shot peened using 0.6 mm conditioned cut steel shots at an average speed of 25 m/s in a conventional shot peening machine, while the harder tempered martensite steel was shot peened using 1.5 mm steel shots at a speed of 50 m/s in an in-house developed shot peening machine. The shot speeds in the conventional shot peening machine were measured using an in-house lidar set-up. The microstructure of each sample was characterized by optical and scanning electron microscopy, and the mechanical properties examined by microhardness and tensile testing. The residual stresses were measured using an Xstress 3000 G2R diffractometer equipped with a Cr Kα x-ray source. The correspondence between the residual stress profile and the gradient structure produced by shot peening, and the relationship between the microstructure and strength, are analyzed and discussed.

Author

R. Yang

Chongqing University

X. Zhang

Technical University of Denmark (DTU)

Dinesh Mallipeddi

Materials and manufacture

N. Angelou

Technical University of Denmark (DTU)

H.L. Toftegaard

Technical University of Denmark (DTU)

Y. Li

Nanjing University of Science and Technology

Johan Ahlström

Engineering Materials

L. Lorentzen

Technical University of Denmark (DTU)

G. Wu

Chongqing University

X. Huang

Technical University of Denmark (DTU)

IOP Conference Series: Materials Science and Engineering

17578981 (ISSN) 1757899X (eISSN)

Vol. 219 1 Art no: UNSP 012046- 012046

Areas of Advance

Transport

Materials Science

Subject Categories

Metallurgy and Metallic Materials

DOI

10.1088/1757-899X/219/1/012046

More information

Latest update

2/28/2018