Strain-induced formation of a gradient nanostructured surface layer on an ultrahigh strength bearing steel

2018 ◽  
Vol 34 (9) ◽  
pp. 1676-1684 ◽  
Author(s):  
K. Zhang ◽  
Z.B. Wang
Keyword(s):  
Surface Layer ◽  
Bearing Steel ◽  
Nanostructured Surface ◽  
Ultrahigh Strength

Low carbon steel with nanostructured surface layer induced by high-energy shot peening

2001 ◽  
Vol 44 (8-9) ◽  
pp. 1791-1795 ◽  
Author(s):  
G Liu ◽  
S.C Wang ◽  
X.F Lou ◽  
J Lu ◽  
K Lu
Keyword(s):  
Surface Layer ◽  
Carbon Steel ◽  
Shot Peening ◽  
Low Carbon Steel ◽  
High Energy ◽  
Low Carbon ◽  
Nanostructured Surface

Thermal Stability of 40Cr Steel with Surface Nanocrystallization

2006 ◽  
Vol 510-511 ◽  
pp. 434-437 ◽  
Author(s):  
Yu Liang Liu ◽  
Tian Ying Xiong ◽  
Ke Yang
Keyword(s):  
Thermal Stability ◽  
Surface Layer ◽  
Nanostructured Materials ◽  
High Thermal Stability ◽  
New Method ◽  
Nanostructured Surface ◽  
Surface Nanocrystallization ◽  
Nanostructured Layer ◽  
40Cr Steel ◽  
Thermal Stability Of

Surface Nanocrystallization(SNC) is a new method of fabricating nanostructured materials while thermal stability is an important problem for the application of nanostructured materials. A nanostructured layer was fabricated on the surface of 40Cr steel by Supersonic Particles Bombarding method, and the variation of microstructure and microhardness of nanostructured layer was studied. Nanostructured surface layer showed high thermal stability.

High Energy Shot Peening of Commercially Pure Titanium TIG Weld Joint

2010 ◽  
Vol 148-149 ◽  
pp. 659-663
Author(s):  
Chun Huan Chen ◽  
Rui Ming Ren
Keyword(s):  
Surface Layer ◽  
Weld Joint ◽  
Shot Peening ◽  
Welded Joint ◽  
Pure Titanium ◽  
High Energy ◽  
Commercially Pure Titanium ◽  
Nanostructured Surface ◽  
Commercially Pure ◽  
Cp Ti

Commercially pure Titanium (CP-Ti) TIG weld joint was treated by means of high energy shot peening (HESP) using a shot peening equipment commonly used in industry. The nanostructured surface layer was characterized by XRD, TEM, SEM and Microhardometer. The results showed that surface nanocrystallization of CP-Ti TIG weld joint were realized by high energy shot peening treatment. The finest grain size in the top surface layer is about 40nm. The hardness of the surface layer is enhanced significantly after shot peening compared with that of the as-welded joint, which resulted in a remarkable surface hardening effect. Surface welded defects such as air pores are eliminated successfully so that relative uniform surface layer was obtained.

Two‐Step Nitriding Behavior of Pure Iron with a Nanostructured Surface Layer

2019 ◽  
Vol 21 (10) ◽  
pp. 1900359 ◽  
Author(s):  
Jian Sun ◽  
Liangyu Mei ◽  
Yi Li ◽  
Yiyuan Lei ◽  
Xiaodong Du ◽  
...  
Keyword(s):  
Surface Layer ◽  
Pure Iron ◽  
Nanostructured Surface

Fabrication and Characterization of Nanostructured Surface Layer of 38CrSi Steel

2007 ◽  
Author(s):  
Shi-Ning Ma ◽  
De-Ma Ba ◽  
Chang-Qing Li ◽  
Fan-Jun Meng
Keyword(s):  
Electron Microscopy ◽  
Grain Size ◽  
Surface Layer ◽  
Grain Refinement ◽  
Fine Particles ◽  
Nanostructured Surface ◽  
Cell Structures ◽  
Strain And Strain Rate ◽  
Transmission Electron ◽  
Average Grain Size

A nanocrystalline surface layer was fabricated on a 38CrSi Steel with tempered sorbite structure by using Supersonic Fine Particles Bombarding (SFPB). The microstructural evolution of SFPB-treated specimens under different processing conditions was characterized by using X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Experimental evidence showed severe plastic deformation and obvious grains refinement were observed and a nanocrystalline surface layer (grain size < 100nm) was found after SFPB treatment. The thickness of nanostructured surface layer varies from a few to about 25μm as treated time increasing from 80s to 240s, but the grain size varies slightly. For the sample treated for 240s, the average grain size of equiaxed nanocrystallites with random crystallographic orientations on the top surface layer is about 16nm. The indexing of diffraction rings indicates nanostructured surface layer consists of ferrite and cementite phases without any evidence of a new phase. The structure size increases gradually from nano-scale to original-scale with an increase of the distance from the top surface layer. In the region about 20–30μm deep from the top surface, the microstructures are mainly composed of 60–100nm roughly equiaxed grains and subgrains. Some subbounsaries are composed of dense dislocation walls (DDWs). In this regime some cell structures are also seen, which are separated by dislocation lines (DTs) and some DDWs. Experimental analysis indicate coarse-grains are gradually refined into nano-sized grains by dislocations activity with gradual increase of strain and strain rate from matrix to treated surface. Both ferrite and cementite phases occur grain refinement. Grain refinement of 38CrSi sample is mainly attributed to the movement of dislocation.

scholarly journals Study of the Mechanical Properties of a Nanostructured Surface Layer on 316L Stainless Steel

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
F. C. Lang ◽  
Y. M. Xing ◽  
J. Zhu ◽  
Y. R. Zhao
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Surface Layer ◽  
Electron Microscope ◽  
316L Stainless Steel ◽  
Nanostructured Surface ◽  
Transmission Electron ◽  
Tensile Process ◽  
The Matrix ◽  
Reverse Analysis

A nanostructured surface layer (NSSL) was generated on a 316L stainless steel plate through surface nanocrystallization (SNC). The grains of the surface layer were refined to nanoscale after SNC treatment. Moreover, the microstructure and mechanical properties of NSSL were analyzed with a transmission electron microscope (TEM) and scanning electron microscope (SEM), through nanoindentation, and through reverse analysis of finite element method (FEM). TEM results showed that the grains in the NSSL measured 8 nm. In addition, these nanocrystalline grains took the form of random crystallographic orientation and were roughly equiaxed in shape. In situ SEM observations of the tensile process confirmed that the motions of the dislocations were determined from within the material and that the motions were blocked by the NSSL, thus improving overall yielding stress. Meanwhile, the nanohardness and the elastic modulus of the NSSL, as well as those of the matrix, were obtained with nanoindentation technology. The reverse analysis of FEM was conducted with MARC software, and the process of nanoindentation on the NSSL and the matrix was simulated. The plastic mechanical properties of NSSL can be derived from the simulation by comparing the results of the simulation and of actual nanoindentation.

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