Yield Point Elongation and Localized Deformation Bands in 22MnB5 Steel at Room Temperature

2013 ◽  
Vol 84 (12) ◽  
pp. 1216-1222 ◽  
Author(s):  
Junying Min ◽  
Jianping Lin
Keyword(s):  
Yield Point ◽  
Room Temperature ◽  
Deformation Bands ◽  
Localized Deformation ◽  
22Mnb5 Steel ◽  
Yield Point Elongation

scholarly journals Spatial and Temporal Characteristics of Propagating Deformation Bands in AA5182 Alloy at Room Temperature

2011 ◽  
Vol 42 (11) ◽  
pp. 3358-3369 ◽  
Author(s):  
R. Nogueira de Codes ◽  
O. S. Hopperstad ◽  
O. Engler ◽  
O.-G. Lademo ◽  
J. D. Embury ◽  
...  
Keyword(s):  
Room Temperature ◽  
Deformation Bands ◽  
Temporal Characteristics ◽  
Aa5182 Alloy ◽  
Spatial And Temporal Characteristics

Heat Assisted Single Point Incremental Forming of Polymer Sheets

2016 ◽  
Author(s):  
Shubhamkar Kulkarni ◽  
Vijay Sarthy Mysore Sreedhara ◽  
Gregory Mocko
Keyword(s):  
Room Temperature ◽  
Incremental Forming ◽  
Single Point ◽  
Future Research ◽  
Single Point Incremental Forming ◽  
Thermoplastic Polymer ◽  
Localized Deformation ◽  
Hot Air ◽  
Polymer Sheets ◽  
Complex Shapes

The objective of this research is to study the improvement in the formability of thermoplastics using heat assisted single point incremental forming. Single point incremental forming is a production process for forming sheet materials without the use of dedicated tooling (dies/molds). The process is an alternative to thermoforming for low volume forming of sheets. It involves forming the final shape through a series of localized incremental deformations. It has been observed that heat assisted techniques have shown an improvement in the formability limits for sheet metals. In this research, this concept has been tested for improving the formability of polymer sheets. Hot air us used to increase the temperature within a localized region in front of the tool. A single point incremental forming device is modified through the development of a specialized tool holder and nozzle which heats the polymer sheet to temperatures higher than the room temperature but below the glass transition temperature of the polymer and applies the forming loads. The results from the experiments are summarized as: i) the formability angle increases of polystyrene from 27 degrees to 46 degrees when comparing room temperature forming to forming at an elevated temperature (170°F–180 °F), ii) a reduction in the forces needed for forming is observed qualitatively, and iii) the surface finish on the formed parts do not show visible change. This demonstrates promise of manufacturing complex shapes from thermoplastic polymer sheets using heat assisted incremental forming. Future research includes 1) simulating the localized deformation of the material to enable process planning, 2) quantifying the forming forces and heat control of the system, and 3) exploring the manufacturing technique to other materials.

Analysis of Orange Peel Defects on Hot-Dip Galvanized High Strength Low Alloy Steel

2014 ◽  
Vol 1004-1005 ◽  
pp. 221-226
Author(s):  
Li Hui Wang ◽  
Di Tang ◽  
Xiang Dong Liu ◽  
Yan Wen Zhang ◽  
Shi Zheng Zhou
Keyword(s):  
Yield Point ◽  
Hsla Steel ◽  
Sheet Steel ◽  
Rolling Direction ◽  
Orange Peel ◽  
High Strength ◽  
Electron Back Scatter Diffraction ◽  
Steel Rolling ◽  
Yield Point Elongation ◽  
Skin Rolling

The surface of hot-dip galvanized high strength low alloy (HSLA) steel easily occurs orange peel in the deformation process. On the other hand, the defects possess a specific directivity and sits at approximately a 45-degree angle to the sheet steel rolling direction. The microstructures and properties of steel specimens with the orange peel defects and the normal were analyzed, which results showed that their microstructures consist of ferrite and few granular pearlite. The yield point elongation of the HSLA steel resulted in the orange peel defects on the surface of sheet stamping and it is associated with skin rolling and stretch rolling process. Further studied on the fine microstructures by means of SEM and electron back scatter diffraction (EBSD) techniques, which was apparent for the defect steel that the orange peel defects were resulted from weak favorable {111} texture might be the key factors aggravating the formation of orange peel defects. It can be concluded that the formation of Cottrell atmospheres caused the yield point elongation by the interaction between dislocation and diffusive solute atoms as basic reason and the directivity of the orange peel defects was related with the LUDERS slip forming. The yield point elongation can be eliminated to avoid the orange peel defects beyond to 1.8% skin-rolling and stretch rolling method with an appropriate annealing technology.

The hardening of copper single crystals by fatigue

1959 ◽  
Vol 251 (1265) ◽  
pp. 186-199 ◽  
Keyword(s):  
Single Crystals ◽  
Yield Point ◽  
Room Temperature ◽  
Maximum Stress ◽  
Fatigue Tests ◽  
Substantial Contribution ◽  
Strong Temperature Dependence ◽  
Copper Single Crystals ◽  
Fatigue Failures ◽  
Additional Hardening

Copper single crystals have been subjected to alternating stresses of such magnitude as would cause complete fatigue failures in 5 x 105 cycles. Slip striations are produced both at 78 and 293 °K and plastic deformation starts in these regions if partially fatigued specimens are extended. In specimens fatigued at 293 °K the material between striations begins to deform at a significantly higher stress than the maximum stress applied during fatigue and yield point phenomena are observed. The flow stress of the yield extension has a strong temperature dependence. Yield point phenomena are less pronounced in specimens fatigued at 78 °K and additional hardening can be produced in such specimens if they are warmed after fatigue to temperatures higher than 200 °K. These observations suggest that point defects make a substantial contribution to the hardening which is observed during fatigue tests at room temperature.

Compressive Properties of Mg-3Al-2Zn-2Y Alloy at Different Strain Rates

2013 ◽  
Vol 327 ◽  
pp. 13-17
Author(s):  
Hao Liang ◽  
Yun Tan ◽  
Fang Ju Zhang ◽  
Kai Zhang
Keyword(s):  
Basal Slip ◽  
Room Temperature ◽  
Strain Rates ◽  
Compressive Properties ◽  
Localized Deformation ◽  
Dislocation Configuration ◽  
Hardening Behavior ◽  
Mixed Dislocation ◽  
Strain Rate Hardening ◽  
Tangled Dislocation

The compressive properties of Mg-3Al-2Zn-2Y alloy at room temperature at strain rates in range of 0.001s-1~4800s-1were investigated. To the alloy compressed at 1300s-1, its basal and non-basal slip produce the mixed dislocation configuration including parallel, bended and tangled dislocation. There is significant twinning in the alloys compressed at 1800s-1and 4800s-1. The flow stress and ultimate trength show the strain rate hardening behavior at the range of 0.001s-1~1800s-1. There appears localized deformation zones formed with recrystal grains and twin crystals in the alloy compressed at 4800s-1, whose mechanical properties are lower than those of alloy compressed at 1800s-1.

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