The Combined Effects of Notches and Microstructure on the Performance of Medium Carbon Steel Breakaway Couplings

1994 ◽  
Vol 116 (1) ◽  
pp. 80-84
Author(s):  
D. P. Henkel ◽  
A. W. Pense
Keyword(s):  
Carbon Steel ◽  
Medium Carbon Steel ◽  
Structural Performance ◽  
Strength Increase ◽  
Combined Effects ◽  
Tempered Martensite ◽  
Average Strength ◽  
Medium Carbon ◽  
Aisi 4130 ◽  
Circumferential Notch

Combined effects of notches and microstructure on the structural performance of medium carbon steel breakaway couplings were discussed. Property troughs commonly associated with tempered martensite embrittlement were characterized as a function of temper for AISI 4130 and 4140 steel couplings. It was observed that a circumferential notch could change the fracture mode from ductile to brittle with no change in tempering condition. Notch-strengthening, a second significant effect, was also observed in similar couplings with an average strength increase of thirty percent. A critical assessment was made of the AASHTO specifications on breakaway couplings used for highway structures and of their interpretation by individual states.

Effect of Preliminary Treatment on Grain Refinement of Medium Carbon Steel Using ECAP at Increased Temperature

2010 ◽  
Vol 638-642 ◽  
pp. 2013-2018 ◽  
Author(s):  
Jozef Zrník ◽  
Sergey V. Dobatkin ◽  
Martin Fujda ◽  
Jan Džugan
Keyword(s):  
Carbon Steel ◽  
Grain Refinement ◽  
Structure Refinement ◽  
Medium Carbon Steel ◽  
Ultrafine Grain ◽  
Initial Structure ◽  
Strength Increase ◽  
Preliminary Treatment ◽  
Medium Carbon ◽  
Treated Steel

By application of thermomechanical controlled rolling and accelerated cooling, the carbon steel grain refinement is limited to levels of ~ 5 μm in steels. The strain assisted or strain induced transformation could be considered for the refining process. The present work, likewise, deals with grain refinement of medium carbon steel containing 0.45 wt pct carbon having different initial microstructure modified by either thermal and/or thermomechanical treatment (TM) prior severe plastic deformation. In case of TM treated steel, structure refinement was conducted in two steps. Preliminary structure refinement has been achieved due to multistep open die forging process which provided total strain of 3. Uniform and fine recrystallized ferrite structure with grain size of the order of 2-5 μm and with nest-like pearlite colonies was obtained. The further grain refinement of steel samples having different initial structure was accomplished during warm Equal Channel Angular Pressing (ECAP) at 400°C. The steel samples of different initial structure were then subjected to six ECAP pressing passes through die channel angle of 120°. The microstructure development was analyzed in dependence of effective strain introduced (εef ~ 2.5 - 4). Employment of this processing route resulted in extensive deformation of ferrite grains where mixture of subgrains and ultrafine grain was found regardless the preliminary treatment of steel. As straining increases the dynamic polygonization and recrystallization became active to form mixture of polygonized subgrains and submicrocrystalline grains having high angle boundaries. The straining and moderate ECAP temperature caused the partial cementite lamellae fragmentation and spheroidization as straining increased. The lamellae cementite spheroidization was more extensive in TM treated steel samples. The tensile behavior was characterized by strength increase for both structural steel states; however the work hardening behavior was modified in steel where preliminary TM treatment was introduced to modified coarse ferrite-pearlite structure.

Tempering kinetics and corrosion resistance of quenched and tempered AISI 4130 medium carbon steel

2021 ◽  
Author(s):  
Aliasghar Mosayebi ◽  
Maryam Soleimani ◽  
Hamed Mirzadeh ◽  
Changiz Dehghanian
Keyword(s):  
Corrosion Resistance ◽  
Carbon Steel ◽  
Medium Carbon Steel ◽  
Medium Carbon ◽  
Aisi 4130

scholarly journals Wear Resistance of Medium Carbon Steel with Different Microstructures

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2015
Author(s):  
Xue Han ◽  
Zhenpu Zhang ◽  
Gary C. Barber ◽  
Steven J. Thrush ◽  
Xin Li
Keyword(s):  
Wear Resistance ◽  
Carbon Steel ◽  
Tribological Performance ◽  
Medium Carbon Steel ◽  
Tempered Martensite ◽  
Medium Carbon ◽  
Debris Particles ◽  
Quenched And Tempered Steel ◽  
Bainite Microstructure ◽  
Martensite Microstructure

In this research, the tribological properties of different microstructures of medium carbon steel produced by either an austempered process or quenched-tempered process are investigated. The as-received samples with annealed microstructure (spherodized) are austempered to obtain a bainite microstructure or quenched-tempered to obtain a tempered martensite microstructure. The tribological performance of these microstructures was studied using a ball-on-disk UMT3 tribometer. The results indicated that both bainite microstructures and tempered-martensite microstructures produced better wear resistance than pearlite microstructures. At the same hardness level, the austempered disk specimens have less cracking due to higher fracture toughness compared to quenched and tempered steel. For the disks, tempered martensite microstructures produced more plastic deformation compared with bainite microstructures. Mild abrasive wear was observed on the harder disks, however, smearing wear was observed on the softer disks. Adhered debris particles were observed on the balls.

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