Tribo-fatigue Behavior of Austempered Ductile Iron MoNiCa as New Structural Material for Rail-wheel System

This research presents the results of tribo-fatigue behavior of austempered ductile cast iron MoNiCa and gives a comparison with standard grades of steel and cast iron. Due to the possibility to combine the castability of cast iron and toughness of steel in one material, new structural material MoNiCa attracted attention of industry and science because of economic benefits and high performance at the different application areas. After successful former experiments the main directions of further development of research for solving relevant practical wear and fatigue problems in rail-wheel system were framed. The complex experimental studies have demonstrated that MoNiCa is consistent with heat treated steels including the rail steels: required tensile strength of rail steel ranges from 1180 MPa to 1280 MPa when rolling surface hardness have to be from 38 HRC to 44 HRC whereas new structural material showed higher tensile strength up to 1400 MPa and slightly higher hardness up to 50 HRC. Herewith the workability of frictional couple cast iron MoNiCa/steel 20MnCr5G exceeds work performance of steel/steel system by 14 %.

Download Full-text

Research on Tensile Behaviour of New Structural Material MoNiCa

Materials Science ◽

10.5755/j01.ms.25.3.23079 ◽

2019 ◽

Vol 25 (3) ◽

pp. 292-296 ◽

Cited By ~ 3

Author(s):

Aliaksandr BAHDANOVICH ◽

Regita BENDIKIENE ◽

Ramunas CESNAVICIUS ◽

Antanas CIUPLYS ◽

Vytautas GRIGAS ◽

...

Keyword(s):

Tensile Strength ◽

Cast Iron ◽

Structural Material ◽

High Efficiency ◽

Critical Mass ◽

Ductile Cast Iron ◽

Carbon Equivalent ◽

Tensile Behaviour ◽

Strength Increase ◽

Heat Treated

This article presents the results of a set of innovative research to analyse a new structural material – steel like austempered ductile cast iron with mechanical properties similar to heat-treated steel, and with technological and exploitation characteristic close to high-strength cast iron with nodular graphite. Specific examples of its high efficiency for the manufacture of critical, mass and heavy-loaded components of modern machinery and equipment are presented. New structural material MoNiCa was tested on tension and was compared to commercial grades of austempered ductile cast irons and heat treated steels. Unconventional behaviour of examined material was observed: with tensile strength increase to almost 1600 MPa the metal became less brittle. Hardness test revealed another distinctive feature of new material that there is no linear relation between strength and hardness increase, different hardness values ~ 40 HRC or ~ 55 HRC can be achieved with the same tensile strength 1000 – 1200 MPa. Microscopic analysis demonstrated of sophisticated structure formed owing to different regimes of austempering treatment. Specific properties emerged from successful ratio of three elements Mo, Ni, and Cu (carbon equivalent), and properly chosen heat treatment modes. DOI: http://dx.doi.org/10.5755/j01.ms.25.3.23079

Download Full-text

The effect of chills thickness to microstructure and surface hardness layer on specimen ductile cast iron

10.1063/5.0073388 ◽

2021 ◽

Author(s):

Natalino Fonseca. D. S Guterres ◽

Rusnaldy ◽

Achmad Widodo ◽

Toto Carwita

Keyword(s):

Cast Iron ◽

Surface Hardness ◽

Ductile Cast Iron

Download Full-text

Joint Strength and its Improvement of Friction Welded Joint Between Ductile Cast Iron and 5052 Al Alloy

JSME 2020 Conference on Leading Edge Manufacturing/Materials and Processing ◽

10.1115/lemp2020-8513 ◽

2020 ◽

Author(s):

Masaaki Kimura ◽

Akira Yoneda ◽

Masahiro Kusaka ◽

Koichi Kaizu ◽

Kazuhiro Hayashida ◽

...

Keyword(s):

Tensile Strength ◽

Cast Iron ◽

Base Metal ◽

Joint Strength ◽

Welded Joint ◽

Weld Interface ◽

Ductile Cast Iron ◽

Al Alloy ◽

High Tensile Strength ◽

Graphite Particles

Abstract To obtain dissimilar joint for easily making multi-material structures, the characteristics of friction welded joint between ductile cast iron (FCD400) and 5052 Al alloy (A5052) was investigated. The relatively high tensile strength of joint was obtained when that was made with a friction speed of 27.5 s−1, a friction pressure of 20 MPa, a friction time of 1.5 s, and a forge pressure of 270 MPa, respectively. However, this joint had approximately 77% in the tensile strength of the A5052 base metal and that was fractured at the weld interface. Although the weld interface had no intermetallic compound layer, the fractured surface at the A5052 side had some graphite particles that were supplied from the FCD400 side. To improve the joint strength, the graphite particles were reduced from the weld faying surface at the FCD400 side by decarburization treatment. The joint had approximately 96% in the tensile strength of the A5052 base metal and that was fractured between the A5052 side and the weld interface. The joint with high tensile strength as well as the possibility improving the fractured point of that were obtained when those were made with opportune friction welding condition and no graphite particles at the weld faying surface of the FCD400 side.

Download Full-text

Microstructure and Properties of Cast Iron with Semi-Solid Process Using Cooling Plate Technique

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.457.79 ◽

2010 ◽

Vol 457 ◽

pp. 79-83 ◽

Cited By ~ 2

Author(s):

Mitsuharu Takita

Keyword(s):

Tensile Strength ◽

Cast Iron ◽

Gray Iron ◽

Ductile Cast Iron ◽

Advanced Materials ◽

Damping Capacity ◽

Cooling Plate ◽

Plate Technique ◽

Wide Range ◽

Semi Solid

Semi-solid metal processing with the cooling plate technique is one of the key technologies for producing advanced materials. The multitude of cast iron families with their wide range of mechanical properties, and relatively low costs combined with the advantage of semi-solid processing allow production of high quality cast components from cast iron. The effect of semi-solid processing using the cooling plate technique on the microstructure and the properties of cast iron is studied. The investigated material is hypo-eutectic, hyper-eutectic gray iron, compacted graphite and ductile cast iron. The results indicated that the microstructure (primary austenite and graphite) becomes finer and more globular by increasing the fraction of solid. The tensile strength of semi-solid processed cast iron is relatively high compared with ordinary cast iron. The values of both the tensile strength and the elongation depend on the fraction of solid. The total fracture strength is observed to depend on the graphite morphology as well as the matrix contribution that mainly depends on fraction of solid. The wear resistance and damping capacity of cast iron were investigated as a function of the relative amount of primary fraction of solid.

Download Full-text

Influence of nickel addition and casting modulus on the properties of hypo-eutectic ductile cast iron

Journal of Mining and Metallurgy Section B Metallurgy ◽

10.2298/jmmb181012023c ◽

2019 ◽

Vol 55 (2) ◽

pp. 283-293 ◽

Cited By ~ 1

Author(s):

E. Colin-García ◽

A. Cruz-Ramírez ◽

G. Reyes-Castellanos ◽

J.A. Romero-Serrano ◽

R.G. Sánchez-Alvarado ◽

...

Keyword(s):

Tensile Strength ◽

Cast Iron ◽

Cooling Rate ◽

Ductile Iron ◽

Ductile Cast Iron ◽

Strength Ratio ◽

Cast Irons ◽

Microstructural Changes ◽

Nodule Count ◽

Nickel Addition

The effect of the casting modulus on the distribution and features of graphite in hypo-eutectic ductile iron unalloyed and alloyed with nickel (0.88 wt %) was studied. The cooling rate of the casting plates of 25.4, 12.7 and 8.5 mm in thickness with a casting modulus of 6.87, 4.46 and 3.31 mm, respectively promotes several microstructural changes, such as cementite precipitation and a noticeable nodule count increment. The nickel addition suppressed the cementite formation and improved the nodule count and nodularity for the three casting modulus evaluated. The nickel addition increased the nodule count in 69, 67 and 128 % for the modulus of 3.31, 4.46 and 6.87 mm, respectively, regarding the unalloyed ductile iron. It was found that the biggest casting modulus produced the biggest nodules with the lowest nodule count for both ductile cast irons. Further to the improvements in the graphite features, the nickel addition allowed to keep almost constant the yield and tensile strength ratio for the different casting modulus.

Download Full-text