Effect of Vacuum Annealing on the Nickel-Based Coatings Deposited on a CGI Cast Iron through Atmospheric Plasma Spraying

Plasma-sprayed nickel-based self-fusion alloy coatings were annealed in a vacuum at 990, 1020 and 1050 °C for 20 min to increase the bonding between the compacted graphite cast iron substrate and coating, as well as the inner cohesion of the coatings. It was found that nickel and chromium diffused between nickel-based alloy coatings and compacted graphite cast iron substrate. A metallurgical translation zone with a thickness up to 1145 μm formed during the vacuum annealing, which resulted in an enhancement of the adhesion between the coating and substrate. The adhesion strength at room temperature was increased from the as-sprayed coating of 33.4 MPa to the annealed one of 163 MPa. Meanwhile, the adhesion strength at 500 °C reached 146 MPa. Conversely, the inner cohesion of the coating was improved with the particles’ interfaces healed after vacuum annealing. The micro-hardness of the annealed coatings was increased to 902 HV from the as-sprayed one of 578 HV.

Download Full-text

Solidification and Room Temperature Microstructure of a Fully Pearlitic Compacted Graphite Cast Iron

Transactions of the Indian Institute of Metals ◽

10.1007/s12666-018-1424-7 ◽

2018 ◽

Vol 71 (11) ◽

pp. 2651-2656 ◽

Cited By ~ 1

Author(s):

Alexandre Freulon ◽

Jon Sertucha ◽

Jacques Lacaze

Keyword(s):

Cast Iron ◽

Room Temperature ◽

Compacted Graphite ◽

Graphite Cast Iron

Download Full-text

THERMOMECHANICAL FATIGUE LIFE OF GRAY AND COMPACTED GRAPHITE CAST IRON ALLOYS

10.26678/abcm.cobem2019.cob2019-1431 ◽

2019 ◽

Author(s):

Douglas Bon ◽

Waldek Wladimir Bose Filho ◽

Wilson Luiz Guesser

Keyword(s):

Cast Iron ◽

Fatigue Life ◽

Thermomechanical Fatigue ◽

Iron Alloys ◽

Compacted Graphite ◽

Graphite Cast Iron

Download Full-text

Formation of the Cast Iron Coatings Plasma-Sprayed at Different Substrate Temperatures

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.44-47.2144 ◽

2010 ◽

Vol 44-47 ◽

pp. 2144-2147

Author(s):

Ya Zhe Xing ◽

Chao Ping Jiang ◽

Hong Chen ◽

Jian Min Hao

Keyword(s):

Cast Iron ◽

Substrate Temperature ◽

Phase Structure ◽

Processing Parameters ◽

Optical Microscope ◽

Atmospheric Plasma ◽

Cross Sectional ◽

The Cross ◽

Plasma Sprayed ◽

Iron Coatings

In this work, three cast iron coatings were produced by atmospheric plasma spraying. During spraying, the surface temperature of three coatings (substrate temperature) was controlled to be averagely 50oC, 180oC and 240oC by changing the processing parameters. X-ray diffraction (XRD) was employed to analyze the phase structure of the starting powder and the coatings. The results showed that the powder was mainly composed of (Fe,Cr)7C3 and martensite and both the spraying processing and the substrate temperature exerted no influence on coating phase structure. An optical microscope (OM) was used to characterize the microstructure of the cross-section and surface of the coatings. It was found that the cross sectional hardness increased with the increase of the substrate temperature due to the improvement in interlamellar bonding.

Download Full-text

Thermal Conductivity Analysis of Compacted Graphite Cast Iron After a Creep Test

Metallurgical and Materials Transactions A ◽

10.1007/s11661-019-05278-x ◽

2019 ◽

Vol 50 (8) ◽

pp. 3697-3704

Author(s):

Wu Yue ◽

Li Jianping ◽

Yang Zhong ◽

Guo Yongchun ◽

Ma Zhijun ◽

...

Keyword(s):

Thermal Conductivity ◽

Cast Iron ◽

Creep Test ◽

Compacted Graphite ◽

Graphite Cast Iron

Download Full-text

On the Primary Solidification of Compacted Graphite Iron: Microstructure Evolution during Isothermal Coarsening

Materials Science Forum ◽

10.4028/www.scientific.net/msf.925.90 ◽

2018 ◽

Vol 925 ◽

pp. 90-97 ◽

Cited By ~ 2

Author(s):

Juan Carlos Hernando ◽

Attila Diószegi

Keyword(s):

Cast Iron ◽

Morphological Evolution ◽

Solidification Process ◽

Primary Phase ◽

Eutectic Solidification ◽

Spheroidal Graphite ◽

Cube Root ◽

Compacted Graphite ◽

Primary Austenite ◽

Graphite Cast Iron

It is widely accepted that in most commercial hypoeutectic alloys, both static mechanical properties and feeding characteristics during solidification, are extremely linked to the coarseness of the primary phase. It is therefore of critical importance to provide tools to control and predict the coarsening process of the dendritic phase present in hypoeutectic melts. The characterization of the primary phase, a product of the primary solidification, has traditionally been neglected when compared to the eutectic solidification characterization in cast iron investigations. This work presents the morphological evolution of the primary austenite present in a hypoeutectic compacted graphite cast iron (CGI) under isothermal conditions. To that purpose, a base spheroidal graphite cast iron (SGI) material with high Mg content is re-melted in a controlled atmosphere and reversed into a CGI melt by controlling the Mg fading. An experimental isothermal profile is applied to the solidification process of the experimental alloy to promote an isothermal coarsening process of the primary austenite dendrite network during solid and liquid coexistence. Through interrupted solidification experiments, the primary austenite is preserved and observed at room temperature. By application of stereological relations, the primary phase and its isothermal coarsening process are characterized as a function of the coarsening time applied. The microstructural evolution observed in the primary austenite in CGI and the measured morphological parameters show a similar trend to that observed for lamellar graphite cast iron (LGI) in previous investigations. The modulus of the primary austenite, Mγ, and the nearest distance between the centre of gravity of neighbouring austenite particles, Dγ, followed a linear relation with the cube root of coarsening time.

Download Full-text