scholarly journals Effect of the Annealing Temperature on the Microstructure and Properties of Ausferritic Nodular Cast Iron

2016 ◽  
Vol 16 (3) ◽  
pp. 43-48 ◽  
Author(s):  
G. Gumienny ◽  
L. Klimek ◽  
B. Kurowska
Keyword(s):  
Heat Treatment ◽  
Cast Iron ◽  
Impact Strength ◽  
Lamellar Structure ◽  
Annealing Temperature ◽  
Nodular Cast Iron ◽  
Iron Matrix ◽  
Secondary Carbides ◽  
Nodular Graphite ◽  
The Impact

Abstract The paper presents the microstructure and selected properties of ausferritic nodular cast iron annealed at the temperature 520 and 550°C. This choice was dictated by the temperatures used in the practice of nitriding. Nodular graphite in cast iron was obtained with use of Inmold process. Cast iron containing molybdenum and copper ensuring obtaining an ausferrite in the cast iron matrix without the use of heat treatment of castings was tested. The effect of annealing temperature on the microstructure and the kind of fracture of the ausferritic nodular cast iron was presented. The effect of an annealing temperature on hardness, impact strength and the microhardness of ausferritic nodular cast iron matrix was shown too. The lamellar structure of phases in the cast iron matrix after annealing has been ascertained. There has been an increase in hardness of an annealed cast iron and microhardness of its matrix. The reduction in the impact strength of the cast iron annealed at 520 and 550°C was approximately 10-30%. Both an increase in the hardness of cast iron as well as an decrease in its impact strength is probably due to the separation of secondary carbides during the heat treatment.

The Influence of Boron on Structure and Mechanical Properties of Bainite Ductile Iron in the Step Austempering in Room Temperature Machine Oil

2010 ◽  
Vol 139-141 ◽  
pp. 235-238
Author(s):  
De Qiang Wei
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Cast Iron ◽  
Impact Strength ◽  
Ductile Iron ◽  
Room Temperature ◽  
Solute Drag ◽  
Ductile Cast Iron ◽  
Treatment Technique ◽  
The Impact

In this paper, the low alloy bainite ductile cast iron has been obtained by a new heat treatment technique of the step austempering in room-temperature machine oil. The effects of element boron, manganese and copper on structure and mechanical properties of the bainite ductile cast Iron in above-mentioned process are investigated. The phenomenon, hardness lag of the alloyed bainite ductile cast Iron, has been discussed. It shows that after the step austempering in room-temperature machine oil, the hardness will increases with the time. It is found that boron and manganese can increase the hardness and reduce the impact strength while copper can increase the impact strength. The results show that reasonable alloyed elements can improve mechanical properties of the bainite ductile cast Iron. Essentially, hardness lag of the alloyed bainite ductile cast Iron is resulted from solute drag-like effect.

scholarly journals Effect of Soft Annealing Treatment on Impact Strength and Hardness of the EN AC-AlSi11 Alloy

2017 ◽  
Vol 17 (3) ◽  
pp. 55-58
Author(s):  
A. Jarco
Keyword(s):  
Heat Treatment ◽  
Impact Strength ◽  
Direct Effect ◽  
Brinell Hardness ◽  
Eutectic Silicon ◽  
Annealing Treatment ◽  
Input Parameters ◽  
The Impact ◽  
Testing Plan

Abstract The paper presents research on the effects of soft annealing parameters on a change of the impact strength KC and Brinell hardness (HB) of the EN AC-AlSi11 alloy. The research has been performed according to the trivalent testing plan for two input parameters – temperature in the range between 280°C and 370°C and time in the range between 2 and 8 hours. The application of such heat treatment improves the plasticity of the investigated alloy. The improvement of the impact strength KC by 71% and the decrease of the hardness HB by 20% was achieved for the soft annealing treatment conducted at a temperature 370°C for 8 hours, compared to the alloy without the heat treatment. A change of the form of eutectic silicon precipitations which underwent refinement, coagulation and partial rounding, had a direct effect on the hardness HB and impact strength KC. The results obtained were used to prepare space plots enabling the temperature and time for soft annealing treatment to be selected with reference to the obtained impact strength KC and hardness HB of the alloy with the heat treatment.

Infiltration Casting and In Situ Fabrication of (Fe,Cr)7C3 Particulates Bundle – Reinforced Iron Matrix Composites

2011 ◽  
Vol 284-286 ◽  
pp. 273-276
Author(s):  
Li Sheng Zhong ◽  
Yun Hua Xu ◽  
Xin Cheng Liu ◽  
Fang Xia Ye ◽  
Jing Lai Tian ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Cast Iron ◽  
Phase Analysis ◽  
Matrix Composite ◽  
Treatment Process ◽  
Heat Treatment Process ◽  
Matrix Composites ◽  
Iron Matrix

The method of infiltration casting plus heat treatment process employing chromium wires and cast iron applied to in-situ synthesized (Fe,Cr)7C3 particulates bundle reinforced iron matrix composites. The phase analysis, microstructure, microhardness and wear-resistance of composite were observed and measured. The results show that it is possible to fabricate (Fe,Cr)7C3 particulates bundle reinforced iron matrix composite produced by this technology, and a special structure which called particulates bundle was fabricated. (Fe,Cr)7C3 particulates bundle were distributed in the forms of granular, lath-shaped and hexagon-shaped in the particulates bundle. The macrohardness of particulates bundle was 52 HRC, and the relative wear resistance of the composites is 2.3—23 times higher than that of the cast iron.

EFFECT OF HEAT TREATMENT ON (Cr, Fe)7C3/γ-Fe COATINGS IN SITU SYNTHESIZED BY VACUUM ELECTRON BEAM IRRADIATION

2017 ◽  
Vol 24 (Supp02) ◽  
pp. 1850028
Author(s):  
BINFENG LU ◽  
YUNXIA CHEN ◽  
MENGJIA XU
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Electron Beam ◽  
Impact Toughness ◽  
Composite Layer ◽  
Test Machine ◽  
Iron Matrix ◽  
Heat Treated ◽  
The Impact

(Cr, Fe)7C3/[Formula: see text]-Fe composite layer has been in situ synthesized on a low carbon steel surface by vacuum electron beam VEB irradiation. The synthesized samples were then subdued to different heat treatments to improve their impaired impact toughness. The microstructure, impact toughness and wear resistance of the heat-treated samples were studied by means of optical microscope (OM), X-ray diffraction (XRD), scanning electron microscope (SEM), microhardness tester, impact test machine and tribological tester. After heat treatment, the primary and eutectic carbides remained in their original shape and size, and a large number of secondary carbides precipitated in the iron matrix. Since the Widmanstatten ferrite in the heat affected zone (HAZ) transformed to fine ferrite completely, the impact toughness of the heat-treated samples increased significantly. The microhardness of the heat-treated samples decreased slightly due to the decreased chromium content in the iron matrix. The wear resistance of 1000[Formula: see text]C and 900[Formula: see text]C heat-treated samples was almost same with the as-synthesized sample. While the wear resistance of the 800[Formula: see text]C heat-treated one decreased slightly because part of the austenite matrix had transformed to ferrite matrix, which reduced the bonding of carbides particulates.

Property and Application of Austempered Ductile Cast Iron

2011 ◽  
Vol 328-330 ◽  
pp. 1297-1300
Author(s):  
Guang Si Luo
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Cast Iron ◽  
Treatment Process ◽  
Nodular Cast Iron ◽  
Ductile Cast Iron ◽  
Heat Treatment Process ◽  
Engineering Material ◽  
High Fatigue ◽  
Austempered Ductile Cast Iron

Austempered ductile cast iron is newly developed engineering material with a favorable combination of comprehensive mechanical properties. Its properties, such as good comprehensive mechanical properties, high fatigue strength, and good fiction and wear characteristics are included. The application of ADI at home and abroad was presented as well. In order to ensure and improve mechanical properties of ADI, it should ensure high rank nodularity in terms of nodular cast iron, improve graphite nodules, reduce segregation and properly cut down the content of silicon and manganese. While in terms of heat treatment, in order to achieve ideal austenite ferrites, stable and reliable heat treatment process as well as relevant equipment is required.

A Study of the Shrinkage and Dilatation during Solidification of Nodular Cast Iron - its Relation to the Morphology of Crystallisation

1984 ◽  
Vol 34 ◽  
Author(s):  
R. Hummer
Keyword(s):  
Cast Iron ◽  
Nodular Cast Iron ◽  
Operating Conditions ◽  
Cooling Curves ◽  
The Real ◽  
Solidification Behaviour ◽  
Feeding Technique ◽  
Nodular Graphite

ABSTRACTThis study deals with the solidification behaviour of cast iron with nodular graphite. By measurement of the “apparent shrinkage” the real feeding requirement can be determined under operating conditions. By means of cooling curves and measurements of dilatation the mode of solidification is established. The results are in accordance with today's knowledge of the morphology of crystallisation and offer an operating hypothesis for feeding technique in practice.

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