Intensive Steel Quenching Methods

EUREKA: Physics and Engineering

2017

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A method for optimizing chemical composition of steel is proposed and a correlation is established to reduce cardinally alloy elements in existing steel grades that results in high compressive residual stresses at the surface of intensively quenched steel parts and increasing strength and ductility of material due to super- strengthening phenomenon. The algorithm of optimization consists in reducing alloy elements in existing alloy steel in 1.5 – 2 times and then lowering step-by-step content of steel, beginning from the most costly alloy element and ending the most cheaper one, until established correlation is satisfied. The range of reduction is minimal and during computer calculations can be chosen as 0,001wt%. The proposed approach can save alloy elements, energy, increase service life of machine components and improve environmental condition. The method is a basis for development of the new low hardenability (LH) and optimal hardenability (OH) steels.

Section: Compressive Residual Stresses and Super-strengthening Phenommentioning

confidence: 99%

A Method for Optimizing Chemical Composition of Steels to Reduce Radically Their Alloy Elements and Increase Service Life of Machine Components

EUREKA: Physics and Engineering

2017

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“…Taken into account these facts, authors [2,5] received an analytical solution of heat conductivity equation (1) with the boundary condition (2), (3) and initial condition (4) which allows calculating duration of transient nucleate boiling process, Eq. (6):…”

Section: Mathematical Model For Quench Process Designmentioning

confidence: 99%

“…At the temperature T 1 developed transient nucleate boiling process starts which continue until temperature T 2 is reached. Duration of transient nucleate boiling process or SRTP was investigated by author [5,6]. SRTP was used to perform austempering in cold liquids [7] that extends sizes of steel parts suitable for austempering and increases cooling rate during performing new technology.…”

Section: The Self-regulated Thermal Processmentioning

confidence: 99%

Investigation of Transient Nucleate Boiling Processes and Their Practical Use in Heat Treating Industry

EUREKA: Physics and Engineering

2017

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In the paper transient nucleate boiling process is widely discussed. It’s unknown previously and investigated by author characteristics create a basis for designing of new technologies which allow receiving super strengthened materials. Obtained results are also used for appropriate software development to be widely applied for control of technological processes and cooling recipes design. A possibility of transition from real heat transfer coefficients (HTCs) to effective HTCs is discussed in the paper too. It is shown that core temperature of steel parts at the end of transient nucleate boiling (self-regulated thermal process (SRTP)) is a linear function of a part dimension when convective heat transfer coefficient during quenching in liquid media is fixed. Also, it is shown that effective Kondrtajev number Kn is a function of part size and convection intensity and is almost linear function for large sizes of steel parts. Surface temperature at the beginning of self-regulated thermal process and at its end is calculated depending on size and intensity of cooling. Based on obtained new results, it is possible to design DATABASE for liquid quenchants using standard Inconel 600 probe combined with the Liscic/Petrofer probe. Obtained results can be useful for engineers and software designers.

“…(1) is based on similarity stress distribution which was for the first time discussed in the publications [13][14][15][16][17][18] and used for software development. If a ratio (1) is satisfied, residual hoop stress distribution in steel component is optimal which is shown in Fig.…”

Section: Steels Of Optimal Hardenabilitymentioning

confidence: 99%

New Ways of Designing Super Strong Materials Based on Use of Alloyed Low Hardenability Steels

Technology transfer: fundamental principles and innovative tech

2017

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Currently, metallurgists are trying to improve mechanical properties of steel by increasing alloy elements in it that require slow cooling in oils or high concentration of water polymers solutions. The paper discusses opposite way in increasing service life of machine components by cardinal decrease alloy elements in steel and providing intensive cooling in locally agitated plain water performed by moving sprayers. The proposed new approach is based on two fundamental phenomena which include creation of high surface compressive residual stresses after quenching and obtaining super - strengthened material in surface layers after intensive cooling. These two factors compensate decrease alloy elements in steel. The paper provides methodology of calculation for achieving maximal effect in residual surface compressive stress formation and super- strengthening of material depending on martensite finish temperature of steel. Effectiveness and benefits are considerable due to saving alloy elements, energy and increasing service life of products. A team of Ukrainian leading specialists is organized to design appropriate software for governing and optimizing hardening processes with the aim of achieving above benefits and make environment clean. New steel and technology of hardening is based on UA Patents No. 109577 and No. 114174