Structure of steel with metastable austenite after thermomechanical treatment on different modes

Author(s):  
G.V. Shlyakhova ◽  
◽  
et al.
2007 ◽  
Vol 534-536 ◽  
pp. 709-712
Author(s):  
Vladimir Dorofeyev ◽  
Anna Sviridova

Powder forging is used for heavy-loaded parts (rings of rolling-contact bearings, gears etc.) production. Rolling contact fatigue is material property values of which characterize possibility of practical utilization of such parts. Rolling contact fatigue of some steels obtained out of prealloyed powders Astaloy CrM, Atomet 4601, Atomet 4901 and powder blends iron-carbon-nickel by hot forging is studied in the present paper. Effect of various kinds of heat and thermomechanical treatment on rolling contact fatigue is determined. Thermomechanical treatment provides optimal values of rolling contact fatigue. In this case steel structure contains up to 40% of retained metastable austenite which is transformed to martensite on trials. Thus typically crack is generated on residual pores and non-metallic inclusions instead of martensite zones in wrought steels.


Author(s):  
M.T. Jahn ◽  
J.C. Yang ◽  
C.M. Wan

4340 Ni-Cr-Mo alloy steel is widely used due to its good combination of strength and toughness. The mechanical property of 4340 steel can be improved by various thermal treatments. The influence of thermomechanical treatment (TMT) has been studied in a low carbon Ni-Cr-Mo steel having chemical composition closed to 4340 steel. TMT of 4340 steel is rarely examined up to now. In this study we obtain good improvement on the mechanical property of 4340 steel by TMT. The mechanism is explained in terms of TEM microstructures4340 (0.39C-1.81Ni-0.93Cr-0.26Mo) steel was austenitized at 950°C for 30 minutes. The TMTed specimen (T) was obtained by forging the specimen continuously as the temperature of the specimen was decreasing from 950°C to 600°C followed by oil quenching to room temperature. The thickness reduction ratio by forging is 40%. The conventional specimen (C) was obtained by quenching the specimen directly into room temperature oil after austenitized at 950°C for 30 minutes. All quenched specimens (T and C) were then tempered at 450, 500, 550, 600 or 650°C for four hours respectively.


1987 ◽  
Vol 48 (C3) ◽  
pp. C3-653-C3-659 ◽  
Author(s):  
M. NIINOMI ◽  
K. DEGAWA ◽  
T. KOBAYASHI

2015 ◽  
Vol 6 (3) ◽  
pp. 65
Author(s):  
E. H. Ouakdi ◽  
A. Soualem ◽  
T. Rechidi ◽  
M. Martiny ◽  
G. Ferron

2020 ◽  
pp. 306-308
Author(s):  
V.S. Bochkov

The relevance of the search for solutions to increase the wear resistance of bucket teeth of excavating machine type front shovel is analyzed. The reasons for the wear of the teeth are considered. It is determined that when excavating machines work for rocks of VIII and IX categories, impact-abrasive wear of the inner side of the teeth and abrasive external wear occurs. It is proved that the cold-work hardening of Hadfield steel (the teeth material), which occurs during the excavating machine teeth work in the rocks of VIII and IX categories, reduces the impact-abrasive wear rate on the inner side of the teeth and does not affect the abrasive wear of the outer. The methods for thermomechanical treatment of the outer side of the excavating machine tooth is proposed. It can increase the wear resistance of Hadfield steel (110G13L) up to 1.7 times and lead to the self-sharpening effect of the tooth due to equalization of the wear rate of the outer and inner parts of the tooth. The efficiency factor of thermomechanical treatment to reduce the of abrasive wear rate of Hadfield steel is experimentally proved.


2020 ◽  
Vol 11 (1) ◽  
pp. 132-139
Author(s):  
Yu. S. Korobov ◽  
O. V. Pimenova ◽  
M. A. Filippov ◽  
M. S. Khadyev ◽  
N. N. Ozerets ◽  
...  

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