Effect of heat treatment on the crack resistance of powder steel SP50Kh3NM

Antsiferov, V. N.; Maslennikov, N. N.; Шацов, А. А.; Platonova, V. B.

doi:10.1007/bf00774847

Cited by 4 publications

(2 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The developed model predicted the values of fracture toughness, friction ratio, and integral linear wear rate of porous steel and bronze [74][75][76][77][78][79][80][81][82][83][84].…”

Section: Lubricated Friction and Wear Processesmentioning

confidence: 99%

Model of Fracture, Friction, and Wear Phenomena of Porous Iron

Шацов

Ryaposov

Larinin

2011

Advances in Tribology

Self Cite

View full text Add to dashboard Cite

Mechanical and tribotechnical features of powdered materials are strongly influenced by pore volume, fracture character, impurities, alloying, concentration inhomogeneity, friction conditions, and other factors. Pores also have influence on acceleration of diffusion processes and reduce undercooled austenite resistance. Annealed in hydrogen, ultra pure iron powder was used to study porous iron features. Toughness fracture and tribotechnical features had nonmonotonic dependence from porosity different from all known dependences got from technical iron powders. Researches brought out the fact that in process of porosity reduction by pressing and annealing cycles, the average dimension of porous is changed. According to the analysis of porous structure were created models of friction, wear, and fracture of pure porous iron.

show abstract

“…The developed model predicted the values of fracture toughness, friction ratio, and integral linear wear rate of porous steel and bronze [74][75][76][77][78][79][80][81][82][83][84].…”

Section: Lubricated Friction and Wear Processesmentioning

confidence: 99%

Model of Fracture, Friction, and Wear Phenomena of Porous Iron

Шацов

Ryaposov

Larinin

2011

Advances in Tribology

Self Cite

View full text Add to dashboard Cite

show abstract

“…For example, the elevated concentration nonuniformity of such materials may lead to the formation of a martensite-bainite structure with an improved combination of strength and toughness [7,8]. Another mechanism that increases the strength, toughness, and fatigue resistance of materials with a nonuniform concentration is described in [9,10] and consists of the decomposition of retained austenite in nickel-rich regions under a static or cyclic load.…”

mentioning

confidence: 98%

Special features of the TRIP effect in powder steels with nonuniform concentration and low nickel content

Antsiferov¹,

Latypov²,

Шацов³

1998

Met Sci Heat Treat

Self Cite

View full text Add to dashboard Cite

The term "TRIP effect" has been suggested by V. Zakei and I. Parker for denoting deformation austenitemartensite Wansformation. At the present time, the term is applied to steels of the austenite -martensite class that have phase transformations under a load. TRIP steels exhibit the best combination of strength and toughness. The present work shows the possibility of realizing the TRIP effect in powder steels at a relatively low concentration of the alloying element (nickel) due to its nonuniform distribution.Elevated mechanical and physical properties in steels of the austenite-martensite and austenite classes were discovered in the second half of the 1960s [1,2]. Strictly speaking, materials like Hadfield steel should also be placed in this class, but the phase transformations under friction have not been discussed in this case.In the present work, we studied powder steels PK-50N4 (0.45 -0.55% C, 4% Ni) and PK-50N6 (0.45 -0.55% C, 6% Ni) manufactured from a polycomponent charge by single pressing at 600 N/ram 2 and sintering in hydrogen (t= 1200~ or vacuum (t = 1300~The elevated density of the specimens was provided by choosing the optimum proportion of the fractions of powder iron and its activity 2 [3]. The retained porosity of the specimens was 4-6%. The concluding heat treatment consisted of quenching from 850-1050~ and tempering at 180~ for 2 h.The density and the porosity of the steels were determined by a pycnometric method (GOST 18898-73) that consisted of weighing specimens of a specified volume. The mechanical properties of tensile tests were determined for flat specimens with a thickness of 6 mm and a length of the functional part equal to 25 ram; the impact toughness was determined for specimens 6 x 6 x 50 mm in size with a distance of 40 mm between the supports. Specimens of this type are used in powder metallurgy in cases where no subsequent mechanical treatment is conducted [4,5].The crack resistance parameter Klc was determined by GOST 25506-82 for preliminarily cracked specimens of type Republican Engineering Center of Powder Metallurgy, Perm, Russia. Active powders are characterized by high compaction rates and sintcring shrinkage.IV by the method of three-point bending using a Heckezt FP I00/1 machine. The correctness of the determination of Kit was checked by the results of tests of specimens 6 x 12 x 70 mm in size (with a 48-mm distance between the supports) and 3 x 6 x 50 mm in size (with a 24-mm distance between the supports). The experimentally determined values of Kit differed by less than 10%: in steel PK-50N4, KIc = 2135 and 2041 N/ram 3/2, and in steel PK-50N6, Ktc=2072 and 2230 N/mm 3/2, respectively.The structure of the steels was studied by metallographic, microdurometric, x-ray, and magnetic methods. The concentration nonuniformity was estimated by the coefficient of variation of the concentrationwhere D is the variance and c is the mean concentration [6].Powder materials are characterized by a specific, different from the conventionally accepted, scale of the nonuniformity of th...

show abstract