Study on copper precipitation during continuous heating and cooling of HSLA steels using electrical resistivity

The growth of columnar grains in fully recristallized IF steel during rapid heat cycles was examined experimentally. The heat cycles consisted of continuous heating with a rate up to 1500°C/s followed by water or air cooling. The employed heating method, as well as the geometrical form of the samples, enabled to obtain the temperature gradients up to 2000°C cm-1. Moreover, temperature measurements and recordings with the aid of ultra-rapid infrared pyrometry made it possible to determine the characteristic temperatures of phase transformations taking place during heating and cooling periods. The main key parameters of the columnar growth, including temperature gradient and the displacement rate of isotherms corresponding to ferrite-austenite and austenite-ferrite phase transformations could also be examined. The results show that the growth of columnar grains already starts at the heating stage at the ferrite/austenite interface moving against the temperature gradient. During the air cooling period, the growth is taking place according to the temperature gradient, together with the austenite/ferrite interface displacement. It was suggested that columnar-like morphology development occurs according to a selective growth mechanism.

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LCA for a Well-Insulated and Airtight House for Two-Generation Family in Whole House with Continuous Heating and Cooling —Part 1: Comparison of LCCO2 Levels in One House in Terms of Insulation Specifications—

Journal of Life Cycle Assessment Japan ◽

10.3370/lca.16.106 ◽

2020 ◽

Vol 16 (2) ◽

pp. 106-129

Author(s):

KATSUCHI Yumeto ◽

TAKAMURA Hideki

Keyword(s):

Continuous Heating ◽

Heating And Cooling ◽

Generation Family ◽

Cooling Part

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CYCLIC THERMORESISTIVITY OF CARBON NANOTUBE YARN/SILICONE RUBBER MATRIX MONOFILAMENT COMPOSITES

10.12783/asc36/35900 ◽

2021 ◽

Author(s):

TANNAZ TAYYARIAN ◽

OMAR RODRIGUEZ-UICAB ◽

TANJEE AFREEN ◽

JANDRO L. ABOT

Keyword(s):

Carbon Nanotube ◽

Electrical Resistance ◽

Room Temperature ◽

Electrical Response ◽

Negative Temperature ◽

Curing Kinetics ◽

Rubber Matrix ◽

Continuous Heating ◽

Average Value ◽

Heating And Cooling

Thermoresistive characterization of CNTY monofilament composites was investigated by using the electrical response of a single carbon nanotube yarn (CNTY) embedded in a silicone polymer forming monofilament composites. Two room temperature vulcanizing (RTV) silicone rubbers with different polymerization mechanisms (OOMOO and Ecoflex) were used as the polymeric matrices. Continuous heating-cooling thermal cycling ranging from room temperature (RT~25 °C) to 80 °C was performed in order to determine the thermoresistive sensitivity, hysteresis and residual fractional change in electrical resistance after each cycle. The thermoresistive response was nearly linear, with negative temperature coefficient of resistance at the heating and cooling zones for CNTY/ OOMOO and CNTY/Ecoflex specimens. The average value of this coefficient at the heating and cooling sections was - 6.65×10-4 °C-1 for CNTY/OOMOO and -7.35×10-4 °C-1 for CNTY/Ecoflex. Both monofilament composites showed a negligible negative residual electrical resistance with an average value of ~ -0.08% for CNTY/OOMOO and ~ -0.20% for CNTY/Ecoflex after each cycle. The hysteresis yielded ~19.3% for CNTY/OOMOO and ~29.2% in CNTY/Ecoflex after each cycle. Therefore, the curing kinetics and viscosity play a paramount role in the electrical response of the CNTY immersed into these rubbery matrices.

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The Assessment Of The Structure And Properties Of High-Carbon Steel Wires After The Process Of Patenting With Induction Heating

Archives of Metallurgy and Materials ◽

10.1515/amm-2015-0218 ◽

2015 ◽

Vol 60 (2) ◽

pp. 855-858 ◽

Cited By ~ 3

Author(s):

S. Wiewiórowska ◽

Z. Muskalski

Keyword(s):

Heat Treatment ◽

Carbon Steel ◽

Induction Heating ◽

High Carbon Steel ◽

Continuous Heating ◽

High Carbon ◽

Temperature Range ◽

Heating And Cooling ◽

Steel Wires ◽

The Wire

Abstract One of the most important types of heat treatment that high-carbon steel wires are subjected to is the patenting treatment. This process is conducted with the aim of obtaining a fine-grained uniform pearlitic structure which will be susceptible to plastic deformation in drawing processes. Patenting involves two-stage heat treatment that includes heating the wire up to the temperature above Ac3 in a continuous heating furnace (in the temperature range of 850÷1050°C) followed by a rapid cooling in a tank with a lead bath down to the temperature range of 450÷550°C. The patenting process is most significantly influenced by the chemistry of the steel being treated, as well as by the temperature and the rate of heating and cooling of the wire rod or wire being patented. So far, heating up to the austenitizing temperature has been conducted in several-zone continuous gas-fired or electric furnaces. Recently, attempts have been made in a drawing mill to replace this type of furnace with fast induction heating, which should bring about an energy saving, as well as a reduced quantity of scale on the patented wire. This paper presents the analysis of the structure and mechanical properties of wires of high-carbon steel with a carbon content of 0.76%C after the patenting process using induction heating for different levels of the coil induction power.

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