Preparation of heavy-section ductile iron with improved mechanical properties through quenching and tempering

2020 ◽  
Vol 111 (5) ◽  
pp. 385-391
Author(s):  
Lifeng Tong ◽  
Qingchuan Zou ◽  
Jinchuan Jie ◽  
Tingju Li ◽  
Zhixin Wang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ductile Iron ◽  
High Strength ◽  
Iron Matrix ◽  
Heavy Section ◽  
Pearlite Content ◽  
Higher Temperature ◽  
Quenching And Tempering ◽  
Tempering Time

Abstract In order to prepare heavy-section ductile iron with high strength and excellent elongation, a series of quenching- tempering experiments was conducted. A relationship between quenching-tempering time and temperature and the contents of martensite and pearlite was established by adjusting different quenching mediums and process parameters, and different microstructures in the iron matrix led to different mechanical properties. The content of martensite in the iron matrix reached over 94% after quenching at 880°C or a higher temperature. Further, the pearlite content could reach over 91% after tempering at 570°C or a higher temperature, thus resulting in improved mechanical properties. The investigated ductile iron yielded mechanical properties of a tensile strength of 970 MPa and an elongation of 6% after quenching in water at 880°C and tempering at 570°C. This will provide more possibilities for the application of heavy-section ductile iron parts.

Effect of Yttrium-Containing Nodulizer on the Microstructure Formation and Mechanical Properties of Heavy Section Ductile Iron Castings

2010 ◽  
Vol 457 ◽  
pp. 73-78 ◽  
Author(s):  
Qin Xin Ren ◽  
Ming You ◽  
Yun Bang Yao ◽  
Guang Min Wen ◽  
Qi Zhou Cai
Keyword(s):  
Mechanical Properties ◽  
Ductile Iron ◽  
Graphite Nodule ◽  
High Melting ◽  
Microstructure Formation ◽  
High Melting Point ◽  
Iron Castings ◽  
Heavy Section ◽  
Long Time ◽  
Pearlite Content

Ductile iron specimens with dimensions of 400mm×400mm ×450mm were prepared by treating the melt with an yttrium-containing nodulizer. The effect of yttrium on microstructure and mechanical properties was investigated, and the formation of degenerate graphite was discussed as well. The results show that the yttrium-containing nodulizer has good nodulization fading resistance for heavy section ductile iron, since the high melting point hexagonal oxide Y2O3 particles were formed from the nodulizer in the melt and those could act as heterogeneous nuclei for graphite nodule for a long time. Segregation of Ti and MgO at grain boundaries broke the austenite shell, resulting in graphite degeneration. When heavy section ductile iron castings with pearlite matrix were cast, graphite nodule size became finer and the nodularity of graphite nodules improved due to the addition of 0.01wt% Sb to the melt, and pearlite content in specimens increased due to alloying with Cu, Cr, Mo. The heavy section ductile iron tool bed was fabricated by treating the melt with the yttrium-containing nodulizer and Ni. The nodularity of the attached block was 85%~90%, tensile strength, elongation and impact toughness were 440MPa, 23.3% and 5.0J/cm2 respectively.

Effect of Sb on the Graphite Morphology and Mechanical Properties in Heavy Section Ductile Iron

2005 ◽  
Vol 475-479 ◽  
pp. 2769-2772 ◽  
Author(s):  
Zhen Hua Li ◽  
Yan Xiang Li
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ductile Iron ◽  
Thermal Simulation ◽  
Simulation System ◽  
Heavy Section ◽  
Graphite Morphology ◽  
Advantageous Effect ◽  
Morphology And Mechanical Properties

In order to clarify the effect of antimony on graphite morphology and mechanical properties in heavy section ductile iron, experiments were carried out using a newly developed thermal simulation system. Results show that with 0.011% addition of antimony, tensile strength of heavy section ductile iron are obviously improved by elimination of graphite degeneration in it, and the effect of antimony is increased when the addition is increased to 0.02%. In the range of 0.01~0.04%, antimony is beneficial to graphite morphology and tensile strength although the advantageous effect on them become not so obvious when addition is exceed 0.02%.

scholarly journals Heat Treatment Evaluation for the Camshafts Production of ADI Low Alloyed with Vanadium

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1036
Author(s):  
Eduardo Colin García ◽  
Alejandro Cruz Ramírez ◽  
Guillermo Reyes Castellanos ◽  
José Federico Chávez Alcalá ◽  
Jaime Téllez Ramírez ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Ductile Iron ◽  
Volume Fraction ◽  
Energy Impact ◽  
Treatment Conditions ◽  
Mold Casting ◽  
Grade 3 ◽  
Good Agreement

Ductile iron camshafts low alloyed with 0.2 and 0.3 wt % vanadium were produced by one of the largest manufacturers of the ductile iron camshafts in México “ARBOMEX S.A de C.V” by a phenolic urethane no-bake sand mold casting method. During functioning, camshafts are subject to bending and torsional stresses, and the lobe surfaces are highly loaded. Thus, high toughness and wear resistance are essential for this component. In this work, two austempering ductile iron heat treatments were evaluated to increase the mechanical properties of tensile strength, hardness, and toughness of the ductile iron camshaft low alloyed with vanadium. The austempering process was held at 265 and 305 °C and austempering times of 30, 60, 90, and 120 min. The volume fraction of high-carbon austenite was determined for the heat treatment conditions by XRD measurements. The ausferritic matrix was determined in 90 min for both austempering temperatures, having a good agreement with the microstructural and hardness evolution as the austempering time increased. The mechanical properties of tensile strength, hardness, and toughness were evaluated from samples obtained from the camshaft and the standard Keel block. The highest mechanical properties were obtained for the austempering heat treatment of 265 °C for 90 min for the ADI containing 0.3 wt % V. The tensile and yield strength were 1200 and 1051 MPa, respectively, while the hardness and the energy impact values were of 47 HRC and 26 J; these values are in the range expected for an ADI grade 3.

scholarly journals Achievement of High Strength and Ductility in Al–Si–Cu–Mg Alloys by Intermediate Phase Optimization in As-Cast and Heat Treatment Conditions

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 647 ◽  
Author(s):  
Bingrong Zhang ◽  
Lingkun Zhang ◽  
Zhiming Wang ◽  
Anjiang Gao
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Intermediate Phase ◽  
High Strength ◽  
Mg Alloys ◽  
Artificial Ageing ◽  
Treatment Conditions ◽  
Eutectic Si

In order to obtain high-strength and high-ductility Al–Si–Cu–Mg alloys, the present research is focused on optimizing the composition of soluble phases, the structure and morphology of insoluble phases, and artificial ageing processes. The results show that the best matches, 0.4 wt% Mg and 1.2 wt% Cu in the Al–9Si alloy, avoided the toxic effect of the blocky Al2Cu on the mechanical properties of the alloy. The addition of 0.6 wt% Zn modified the morphology of eutectic Si from coarse particles to fine fibrous particles and the texture of Fe-rich phases from acicular β-Fe to blocky π-Fe in the Al–9Si–1.2Cu–0.4Mg-based alloy. With the optimization of the heat treatment parameters, the spherical eutectic Si and the fully fused β-Fe dramatically improved the ultimate tensile strength and elongation to fracture. Compared with the Al–9Si–1.2Cu–0.4Mg-based alloy, the 0.6 wt% Zn modified alloy not only increased the ultimate tensile strength and elongation to fracture of peak ageing but also reduced the time of peak ageing. The following improved combination of higher tensile strength and higher elongation was achieved for 0.6 wt% Zn modified alloy by double-stage ageing: 100 °C × 3 h + 180 °C × 7 h, with mechanical properties of ultimate tensile strength (UTS) of ~371 MPa, yield strength (YS) of ~291 MPa, and elongation to fracture (E%) of ~5.6%.

Effects of Sr Addition on Mechanical Properties and Microstructure of Mg-6Al Magnesium Alloy

2011 ◽  
Vol 686 ◽  
pp. 120-124
Author(s):  
Jin Ping Fan ◽  
She Bin Wang ◽  
Bing She Xu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Magnesium Alloy ◽  
Strengthening Mechanism ◽  
Microstructure And Mechanical Properties ◽  
Higher Temperature ◽  
Lower Temperature

The effects of Sr addition on the mechanical properties and microstructure of Mg-6Al mag- nesium alloy both at 25 °C and at 175 °C were investigated by means of OM, SEM and EDS and XRD. Upon the Sr addition of 2%, the tensile strength was increased by 7.2% to 184.4MPa at 25 °C, while it was increased by 30% to 155.4MPa at 175 °C. The strengthening mechanism of Mg-6Al-xSr at lower temperature (25 °C) was different from that at higher temperature (175°C). The results show that the addition of strontium effectively improved the microstructure and mechanical properties of magnesium alloy.

Effect of Heat Setting Methods on Structures and Properties of High Strength Polyvinyl Alcohol Fibre

2015 ◽  
Vol 815 ◽  
pp. 643-648
Author(s):  
Yin Zhu ◽  
Jiong Xin Zhao
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Polyvinyl Alcohol ◽  
Setting Time ◽  
High Strength ◽  
Single Fibre ◽  
X Ray Diffraction ◽  
Heat Setting ◽  
Heat Treated ◽  
Setting Process

The effect of heat setting methods on the structures and mechanical properties of high strength polyvinyl alcohol (PVA) fibre is studied in this article. The microstructure and mechanical properties of heat treated PVA fibre is investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and single fibre electronic tensile strength tester. Results show that the heat setting method with constant tension is a good heat setting method which can largely enhance the tensile strength of PVA fibre. During the heat setting process, the mechanical properties of PVA fibre are greatly affected by the temperature, tension and setting time. When the temperature is 220°C, tension is 5cN/dtex and setting time is 90sec, the tensile strength of PVA fibre increases from 12.0cN/dtex to 16.4cN/dtex in compare with the PVA fibre without heat setting

scholarly journals Evaluation of Microstructure and Selected Mechanical Properties of Laser Beam Welded S690QL High-Strength Steel

2018 ◽  
Vol 18 (3) ◽  
pp. 34-42 ◽  
Author(s):  
L. Tuz
Keyword(s):  
Mechanical Properties ◽  
Laser Beam ◽  
High Strength Steel ◽  
High Strength ◽  
Fine Grain ◽  
Steel Material ◽  
Bainitic Structure ◽  
Haz Width ◽  
Quenching And Tempering ◽  
Softened Zone

AbstractThe paper presents results of microstructure and mechanical properties investigation of laser beam welded high-strength steel. Material for test was non-alloyed steel with yield strength of 690 MPa after quenching and tempering in delivery condition. Research carried out on the butt-welded joints shows fine-grain martensitic-bainitic structure of base metal and in the weld. Investigations of mechanical properties revealed the softened zone in HAZ where the hardness decrease without microstructural changes was observed. Moreover, an influence of softened zone and HAZ width on impact strength was observed where the occurrence of lower hardness led to fracture path deviation phenomenon.

scholarly journals Ausferritic (bainitic) cast iron: Harmonization of international standard ISO 17804 in application to the conditions of Belarus

2021 ◽  
pp. 56-72
Author(s):  
A. I. Pokrovskii ◽  
B. B. Khina ◽  
O. A. Tolkacheva
Keyword(s):  
Tensile Strength ◽  
Cast Iron ◽  
Ductile Iron ◽  
High Strength ◽  
State Committee ◽  
Spheroidal Graphite ◽  
Cast Irons ◽  
International Standard ◽  
Industrial Enterprises ◽  
State Organizations

The experience of the Physico-technical Institute (PhTI) of the National Acdemy of Sciences of Belarus in the harmonization of international standard ISO 17804 (Founding – Ausferritic spheroidal graphite cast irons – Classification) and development of the Belorussian analogue STB ISO is described. The reasons for the choice of austempered ductile iron (ADI) as an object for standard harmonization are presented: it is the most promising cast iron in comparison with gray and classical ductile iron. The work procedure on harmonization is described: how to include the task into the State Plan on standardization, specificity of translation of the text, peculiarities of with state organizations responsible for approbation of standards such as Belorussian Institute for Standardization and Certification (BelGISS) and State Committee on Standards (Gosstandart), writing a summary of external reviews, working with critical comments from potential users. It is outlined that any foreign standard does not exists independently but is closely connected with at least 10 to 20 other standards. Thus, harmonization necessitates coordination with other standards and sometimes even with handbooks by adding annexes to the main text. The importance of a proper choice of the standard status is outlined: identical (ID) or modified (MOD). Developing an identical standard is prestigious but difficult because is requires harmonization of all the referenced standards, which is a very labor-consuming procedure. It is argued that the most suitable is ‘intermediate’ variant: adopting the authentic text of the international standard (in high-quality translation) but with annexes reflecting national specificity in this area. As a result, a harmonized standard is developed which, for the first time in Belarus, standardize the tensile strength of 800 MPa in combination with the elongation of 10 % and the tensile strength of 1400 MPa in combination with the elongation of 1 % for cast irons.The annual demand for ADI in Belarus is estimated as about 10,000 ton. It is shown that in Belarus, where about 60 industrial enterprises have a foundry and almost every engineering plant has a heat-treatment shop, austempered ductile cast (ADI), which features a high strength, can successfully compete with rolled steel in certain applications.

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