Surface severe plastic deformation of AISI 304 via conventional shot peening, severe shot peening and repeening

Effects of ultrasonic nanocrystalline surface modification (UNSM) technique on the tribological behavior of sintered Cu-based alloy

In this study, the shot peening parameters which directly influence the arc height of the Almen strip and its characteristics are optimized within the context of Almen intensity, surface roughness and surface hardness via response surface methodology. Determination of the Almen intensity by trial and error method depending on the experience of the technician (measuring the arc height of Almen strips by changing the parameters repeatedly for each shot peening process) makes the optimization approaches valuable. The optimization is considered to perform by selecting surface roughness and surface hardness as the responses in order to classify the shot peening processes by taking into consideration of wide range of plastic deformation level. The effect of input parameters air pressure, shot diameter and peening duration on the Almen intensity, surface roughness and surface hardness is to be determined by using ANOVA regression analysis. Based on the estimated models, optimum peening conditions are introduced via response optimizer. The model adequacy is verified by the confirmation tests.

Optimization of shot peening parameters by response surface methodology

Characterization of surface layer in TC17 alloy treated by air blast shot peening

Enhancing surface layer properties of an aircraft aluminum alloy by shot peening using response surface methodology

Micro-structure and surface layer properties of 18CrNiMo7-6 steel after multistep shot peening

Uniformity of residual stress distribution on the surface of S30432 austenitic stainless steel by different shot peening processes

Effect of prestress state on surface layer characteristic of S30432 austenitic stainless steel in shot peening process

The invention relates to a novel spring pre-strengthening finishing composite shot blasting method. The method includes that a spring is subjected to pre-strengthening finishing composite shot blasting by a shot blasting machine, the pre-strengthening finishing composite shot blasting includes three processes, the shot blasting strength is 0.23Amm in the first process, the shot blasting strength is 0.45Amm in the second process, the shot blasting strength is 0.15Amm in the third process, and shot blasting mediums of three-time shot blasting are same to obtain a processed spring product. Compared with shot blasting methods in prior art, the novel spring pre-strengthening finishing composite shot blasting method has the advantages that the beneficial effect of residual compressive stress is increased, and negative influences caused by surface roughness of a part can be avoided to greatest degree.

Novel spring pre-strengthening finishing composite shot blasting method

The thermal relaxation behavior of residual stress and microstructure at elevated temperatures in S30432 austenite steel after shot peeningwas investigated by X-ray residual stress analyzer. The effect of the exposure time and the applied temperature on the residual stress andmicrostructure relaxation was particularly analyzed and discussed. A signiﬁcant decrease of the residual stress values and peak breadth wasobserved in the ﬁrst period of exposure time, followed by slowing down and then stabilization. It was also observed that a higher appliedtemperature produced greater relaxation. The relaxation behavior could be described by Zener­Wert­Avrami function. The thermal stability ofmicrostructure was higher than that of the residual stress. Both of the activation enthalpy of residual stress and microstructure relaxation werehigher than that of iron self-diffusion in £-Fe. [doi:10.2320/matertrans.M2012058](Received February 15, 2012; Accepted March 26, 2012; Published May 25, 2012)Keywords: thermal relaxation, residual stress, microstructure, S30432 austenite steel

K. Zhan

Papers

Micro-structure and surface layer properties of 18CrNiMo7-6 steel after multistep shot peening

Uniformity of residual stress distribution on the surface of S30432 austenitic stainless steel by different shot peening processes

Effect of prestress state on surface layer characteristic of S30432 austenitic stainless steel in shot peening process

Novel spring pre-strengthening finishing composite shot blasting method

Thermal Relaxation Behavior of Residual Stress and Microstructure in Shot Peened S30432 Steel at Elevated Temperatures