scholarly journals The Effect of Cryogenic Treatment on the Punch Wear and the Hole Edge Geometry

2020 ◽  
Vol 44 (2) ◽  
pp. 45-57
Author(s):  
Yusuf Arslan
Keyword(s):  
Cryogenic Treatment ◽  
Hole Edge ◽  
Edge Geometry ◽  
Punch Wear

scholarly journals The Effects of Cryogenic Process on the AISI M2 Punch Materials and on the Hole Edge Geometry of the DIN EN 10111-98 Sheet Metal Control Arm Parts

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Yusuf Arslan
Keyword(s):  
Sheet Metal ◽  
Tool Steel ◽  
Retained Austenite ◽  
Hole Edge ◽  
Edge Geometry ◽  
Weight Losses ◽  
Cryogenic Process ◽  
Measuring Machine ◽  
Hole Geometry ◽  
Punch Wear

In this study, not only the effects of cryogenic processing on the wear of AISI M2 punches but also the effects of punch wear on the hole edge geometry of DIN EN 10111-98 sheet metal control arm parts were investigated. The hole geometry changes are generally associated with punch wear and process parameters. Piercing operations were performed using eccentric press on 2.5-mm-thick sheet metal control arm parts with circular and slot AISI M2 tool steel punches. The punches were traditionally heat treated. The others were cryogenically treated at −145°C in addition to the conventional heat treatment. Weight losses were measured for punch wear assessments; furthermore, SEM and OM images were analyzed. The hole edge geometries of the selected parts were measured with a contour measuring machine in the specified number of blanks. So, no damage was done to the products for measurements. The cryogenic process resulted in a significantly low amount of retained austenite and caused uniformly distributed thin carbide precipitates. Reduction of retained austenite and formation of fine carbide particles led to increase in hardness values. It was found that untreated circular punch wear weight losses were approximately 40% higher than those of cryogenically treated samples. The untreated slot punch change rate was about 106% higher than that of the cryogenically treated samples. The wear process during the punching was faster and greater for the untreated punches. Fatigue microcracks were more common at the cutting edge of the untreated punches. However, abrasive wear was generally observed in cryogenically treated punches. The edge geometry values in the circular holes were at least two times higher than those in the slot holes of untreated samples. At the end of the industrial piercing process, it was determined that the M2 tool steel punch wear rates were decreased by cryogenic treatment, and the size changes of the hole geometry of the punches of the DIN EN 10111-98 control arm parts were more economic and with a better quality.

TEM observations of surface-step and hole-edge faceting in acid-etched and annealed MgO thin foils

1993 ◽  
Vol 51 ◽  
pp. 1134-1135
Author(s):  
Simon King ◽  
C. Barry Carter
Keyword(s):  
Marked Contrast ◽  
Aqua Regia ◽  
Surface Step ◽  
Smoke Particle ◽  
Hole Edge ◽  
Thin Foils ◽  
Surface Steps ◽  
Unit Cells ◽  
Reflection Electron Microscopy ◽  
Similar Preparation

Surface-steps formed during the cleavage of MgO on {100} planes, the smaller steps of which may be of atomic height, have been observed in Reflection-Electron Microscopy investigations to be accurately aligned along <001> directions. Steps of atomic height also have been identified on MgO smoke-particle platelets; these steps may be curved or straight, with the straight steps showing evidence for faceting along <001>. Reference also is made to faceting along <011> and <012> directions. Straight steps ∼2 unit cells high, with edges along <100> also have been imaged by High-Resolution Profile-Imaging at the peripheries of MgO smoke microcubes. After etching in aqua-regia and annealing in air, however, high densities of “large” steps several unit cells high, as well as numerous holes, are formed. It is faceting in these foils that is reported here.As can be seen in fig 1, obvious faceting of the surface-step traces is extremely rare in these foils, in marked contrast to substrates such as LaAlO3 and SrTiO3, on which surface-step traces facet readily after a similar preparation treatment.

Role of tip and edge geometry on vortex asymmetry

AIAA Journal ◽  
2001 ◽  
Vol 39 ◽  
pp. 539-543 ◽  
Author(s):  
T. Lim ◽  
K. B. Lua ◽  
S. C. Luo
Keyword(s):  
Edge Geometry

Effect of cryogenic treatment on the microstructure and wear behavior of a T-42 tool steel

2015 ◽  
Vol 57 (4) ◽  
pp. 306-310 ◽  
Author(s):  
Lakhwinder Pal Singh ◽  
Jagtar Singh
Keyword(s):  
Tool Steel ◽  
Wear Behavior ◽  
Cryogenic Treatment

CRYOSURGERY IN THE TREATMENT OF PATIENTS WITH BONE TUMORS

2019 ◽  
Vol 65 (2) ◽  
pp. 165-171
Author(s):  
Aleksey Belyaev ◽  
Georgiy Prokhorov ◽  
Anna Arkhitskaya
Keyword(s):  
Liquid Nitrogen ◽  
Bone Tumors ◽  
Cryogenic Treatment ◽  
Long Term Results ◽  
Bone Lesions ◽  
Giant Cell Tumors ◽  
Primary Bone Tumors ◽  
Circulation Circuit ◽  
Recent Emergence ◽  
Primary Bone

A review of the literature shows that surgical procedures will remain the standard treatment for primary bone tumors. Analysis of studies on the assessment of long-term results shows that additional double cryogenic treatment of the curettage cavity can improve the treatment outcomes of patients with giant cell tumors, dysplastic diseases and some forms of malignant lesions. The traditional execution of the procedure is associated with the open installation of liquid nitrogen in the bone cavity, which requires special skills in handling aggressive refrigerant from the staff and does not exclude complications. In case of multiple metastatic bone lesions, surgical treatment is not indicated. The recent emergence in clinical practice of new equipment with a closed liquid nitrogen circulation circuit inside cryoprobes resumes interest in cryoabla-tion of bone tumor lesions using modern minimally invasive puncture cryotechnology and expanding indications for its use in patients with severe comorbidities.

The Effects of Quenching and Tempering Treatment on the Hardness and Microstructures of a Cold Work Steel

2019 ◽  
Vol 4 (1) ◽  
pp. 286-294
Author(s):  
László Tóth ◽  
Réka Fábián
Keyword(s):  
Heat Treatment ◽  
Retained Austenite ◽  
Elevated Temperatures ◽  
Cryogenic Treatment ◽  
Cold Work ◽  
Chromium Steel ◽  
Primary Carbide ◽  
Tempering Temperature ◽  
Tempering Treatment ◽  
Primary Carbides

The X153CrMoV12 ledeburitic chromium steel characteristically has high abrasive wear resistance, due to their high carbon and high chromium contents with a large volume of carbides in the microstructure. This steel quality has high compression strength, excellent deep hardenability and toughness properties, dimensional stability during heat treatment, high resistance to softening at elevated temperatures. The higher hardness of cryogenic treated samples in comparison with conventional quenched samples mean lower quantity of retained austenite as at samples quenched to room temperature and tempered in similar condition. In the microstructure of samples were observed that the primary carbide did not dissolve at 1070°C and their net structure have not been changed during to heat treatment. During to tempering at high temperature the primary carbides have become more and more rounded. After low tempering temperature in martensite were observed some small rounded carbides also, increasing the tempering temperature the quantity of finely dispersed carbides increased, which result higher hardness. The important issues in heat treatment of this steels are the reduction or elimination of retained austenite due to cryogenic treatment.

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