Selection of direct cooling conditions for automotive lever made of microalloyed steel

Skubisz, P.; Sińczak, J.; Skowronek, T.; Rumiński, M.

doi:10.1016/j.acme.2012.08.004

Cited by 9 publications

(6 citation statements)

References 9 publications

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“…The comparison of the studied 0.25 wt% C, 0.04–0.12 V cast steels to 0.30–0.38 wt% C hot rolled and forged ones with similar V contents showed similar strength and ductility. This is a significant advantage of our steels, as the elongation to failure in the cast steels might be expected to be lower than that in the deformed ones.…”

Section: Discussionmentioning

confidence: 80%

Vanadium Microalloyed 0.25 C Cast Steels Showing As-Forged Levels of Strength and Ductility

Kostryzhev

Morales-Cruz

Zuno-Silva

et al. 2016

steel research int.

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Application of cast steels instead of hot forged or rolled ones will significantly decrease manufacturing costs and the final product price. However, low levels of mechanical properties in cast steels, especially ductility, can slow down the substitution of forged and rolled steels with the cast. In the present work, the authors study the effect of 0.01-0.12 wt% vanadium additions on the microstructure and mechanical properties of 0.25 wt% C cast steels. The yield stress, ultimate tensile strength, and elongation to failure in the studied cast steels are 730-750 MPa, 955-1002 MPa, and 12.3-21.5%, respectively, which correspond to those in hot forged and rolled steels with similar compositions. So, high property values in the 0.25 wt% C cast steels are shown here for the first time. The simultaneous increase in strength and ductility with an increase in V content follow a decrease in pearlite fraction, interlamellar spacing, and average pearlite area size; an increase in amount of degenerated pearlite; an increase in V-rich particle volume fraction and number density in ferrite and pearlite; the occurrence of interphase precipitation (in 0.12 wt% V steel), and an increase in dislocation density in ferrite and pearlite.

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Section: Discussionmentioning

confidence: 80%

Vanadium Microalloyed 0.25 C Cast Steels Showing As-Forged Levels of Strength and Ductility

Kostryzhev

Morales-Cruz

Zuno-Silva

et al. 2016

steel research int.

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“…The subject of the research were newly elaborated microalloyed HSLA-type steels with chemical composition presented in Table 1. Chemical composition of examined steels was developed on the basis of detailed analysis of the literature [4,5,7,15,24,32,37,39] in terms of the production of forgings using thermomechanical treatment method.…”

Section: Methodsmentioning

confidence: 99%

“…In case of HSLA-type steels, the increase in strength is related to grain refinement and precipitation hardening by dispersive particles of carbides, nitrides and carbonitrides [9,10,41,42]. The analysis of publications related to manufacturing of forgings with the use of thermomechanical treatment reveals that the studies conducted so far have been focused on introducing V [15,24,32,37] and Ti and V [4,5,7,39] microadditions into steel. Very few studies on combined application of Nb, Ti and V creates the necessity to perform more detailed analysis of understanding of the complex interaction of MXtype interstitial phases containing Nb, Ti and V and the process of their precipitation.…”

Section: Introductionmentioning

confidence: 99%

Thermodynamic Analysis of Precipitation Process of MX-type Phases in High Strength Low Alloy Steels

Opiela¹

2021

Adv. Sci. Technol. Res. J.

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The paper presents the results of thermodynamic analysis of precipitation process of MX-type interstitial phases in austenite. The subject of the investigation were two newly developed high strength low alloy microalloyed steels with similar concentration of C and N and with diversified amount of Nb, Ti and V microadditions. Thermodynamic analysis of the state of phase equilibrium of structural constituents, taking into consideration the austenite of investigated microalloyed steels, was mainly focused on analytic calculations of chemical composition of austenite and the content and chemical composition of potential MX-type interstitial phases (M -metal, X -metalloid) as a function of heating or cooling temperature. The analysis of precipitation process of complex carbonitrides in austenite under thermodynamic equilibrium conditions has allowed to define stoichiometric compositions of carbonitrides as a function of temperature along with determination of their volume portion. This study was based on the model proposed by Hillert and Staffanson, which was subsequently developed by Adrian. The results of performed investigation can be used to develop the appropriate parameters of thermomechanical treatment of metallurgical products from the tested HSLA-type steels.

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“…The reduction ratio in forging trials and cooling rate in cooling were selected with aid of numerical finite element method (FEM) analysis of processing of real industrial process. After forging, direct cooling was carried out with use of laboratory equipment QuenchTube Lab, designed for simulation of industrial continuous cooling cycles (Skubisz et al, 2012). The hot forged samples were transferred to the cooling chamber directly after deformation, recording the temperature time plot measured with thermocouple and pyrometers.…”

Section: Hot Forging and Direct Cooling Testsmentioning

confidence: 99%

Properties of direct-quenched aircraft forged component made of ultrahigh-strength steel 300M

Skubisz¹,

Sińczak²

2018

AEAT

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Purpose This paper aims to investigate the possibilities and determination of hot and warm forging of ultrahigh-strength steel 300M and subsequent quenching with accelerated air. Analysis of microstructure and mechanical properties of forged steel 300M focused on investigation of the effect of processing conditions on final properties, such as strength, impact strength and hardness, taking into consideration temperature gradients and within-part strain nonuniformity occurring in forging and direct cooling of aircraft landing gear. Design/methodology/approach The research involved semi-industrial physical modeling of hot deformation and direct cooling, aided with numerical analysis of both deformation and kinetics of phase transformations on cooling, with process conditions determined on the basis of numerical simulation of industrial process. Examination of forged and quench-tempered samples involved testing mechanical properties (tensile properties, hardness and impact strength) and microstructure. Findings Three major findings were arrived at: first, assessment of the effects of energy-saving method of cooling conducted directly after forging. Second, tensile properties, hardness and impact strength, were analyzed on the background of microstructure evolution during hot-forging and direct cooling; hence, applied temperature and cooling rates refer to actual condition of the material including varied deformation history. Third, the accelerated air cooling tests were carried out directly after forging with accurately measured and described cooling efficiency, which enabled the acquisition of data for heat treatment simulation with use of untypical cooling media. Research limitations/implications The conclusions formulated on the strenght of studies carried out in semi-industrial conditions with the use of model samples, despite strain and strain rate similarity, wait for full-scale verification in industrial conditions. The direct cooling tests carried out in semi-industrial conveyor Quenchtube are of cognitive value. Industrial realization of the process for the analyzed part calls for special construction of the cooling line and provision of higher cooling rate for heavy sections. Practical implications The results present microstructure properties’ relations for good-hardenability grade of steel, which is representative of several similar grades used in aircraft industry, which can support design of heat treatment (HT) cycles for similar parts, regardless of whether direct or conventional quenching is used. As they illustrate as-forged and direct-cooled microstructure and resultant mechanical properties, the studies concerning processing the steel of areas of lower temperature are transferable to warm forging processes of medium-carbon alloy steels. The geometry of the part analyzed in the case study is typical of landing gear of many aircrafts; hence, there is the high utility of the results and conclusions. Social implications The direct heat treatment technologies based on utilization of the heat attained in the part after forging allow significant energy savings, which besides cost-effectiveness go along with ecological considerations, especially in the light of CO2 emission reduction, improving economical balance and competitiveness. The presented results may encourage forgers to use direct cooling, making use of the heat attained in metal after hot forging, for applications to promote environmentally friendly heat treatment-related technologies. Originality/value Direct heat treatment typically seems to be reserved for micro alloyed steel grades and sections small enough for sufficient cooling rates. In this light, taking advantage of the heat attained in forged part for energy-saving method of cooling based on direct quenching as an alternative to traditional Q&T treatment used with application to relatively heavy sections is not common. Moreover, in case the warm-work range is reached in any portion of the forged part, effect of direct cooling on warm-forged material is addressed, which is a unique issue to be found in the related studies, whereas in addition to warm forging processes, the results can be transferable to coining, sizing or shot peening operations, where gradient of properties is expected.

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Selection of direct cooling conditions for automotive lever made of microalloyed steel

Cited by 9 publications

References 9 publications

Vanadium Microalloyed 0.25 C Cast Steels Showing As-Forged Levels of Strength and Ductility

Vanadium Microalloyed 0.25 C Cast Steels Showing As-Forged Levels of Strength and Ductility

Thermodynamic Analysis of Precipitation Process of MX-type Phases in High Strength Low Alloy Steels

Properties of direct-quenched aircraft forged component made of ultrahigh-strength steel 300M

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