Microstructure characteristics of Ti–43Al alloy during twin-roll strip casting and heat treatment

In this paper, effect of heat treatment on the microstructures and wear properties of laser alloying (LA) composites is investigated. LA of the T - Co 50/ FeSi / TiC / TiN / CeO 2 mixed powders on substrate of 45 steel can form the hard composites, which increased the wear resistance of substrate greatly. Such LA composites were investigated by means of a scanning electron microscope (SEM) and a transmission electron microscope (TEM). The tempering promoted the growth of the block-shape hard phases, favoring an enhancement of the integrity of block-shape hard phases; and tempering also improved greatly the formation mechanism, guarantying the composites to have enough ability of intensity transfer. This research provided essential experiment and theoretical basis to promote the application of the laser and heat treatment technologies in the field of surface modification.

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Self-organizing fuzzy controller for the molten steel level control of a twin-roll strip casting process

Journal of Intelligent Manufacturing ◽

10.1007/s10845-009-0324-4 ◽

2009 ◽

Vol 22 (4) ◽

pp. 619-626 ◽

Cited By ~ 3

Author(s):

Hung-Yi Chen ◽

Shiuh-Jer Huang

Keyword(s):

Molten Steel ◽

Fuzzy Controller ◽

Casting Process ◽

Strip Casting ◽

Level Control ◽

Twin Roll ◽

Self Organizing

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Crack Formation Mechanism of High Silicon Steel during Twin-Roll Strip Casting

Materials Science Forum ◽

10.4028/www.scientific.net/msf.898.1276 ◽

2017 ◽

Vol 898 ◽

pp. 1276-1282

Author(s):

Wen Li Hu ◽

Yuan Xiang Zhang ◽

Guo Yuan ◽

Guo Dong Wang

Keyword(s):

Formation Mechanism ◽

Crack Formation ◽

Silicon Steel ◽

Strip Casting ◽

Dominant Factor ◽

Transverse Cracks ◽

High Silicon Steel ◽

High Silicon ◽

Gas Gap ◽

Twin Roll

High silicon steel was fabricated by twin-roll strip casting. The cracks on the surfaces of the processed strips were obtained and analyzed by digital camera after series of surface treatment. Optical microscopy (OM) and scanning electron microscopy (SEM) were used to observe and characterize the microstructure nearby crack and fracture surface along the normal direction, respectively, and the crack formation mechanism was further analyzed in conjunction with processing parameters utilized during twin-roll strip casting process. The results indicated that morelongitudinal cracks along the rolling direction were observed in comparison with transverse cracks along the transverse direction on the strip surfaces. Trans granular and intergranular fracture modes both worked during the formations of longitudinal and transverse cracks on the processed strips. The dominant factor causing the formation of crack on the surface of the processed strips was the inhomogeneous transfer of heat during casting and rolling. The inhomogeneous transfer of heat induced by gas gap during casting resulted in variations of dendrite length and secondary dendrite spacing (SDAS). Meanwhile, the casting velocity influenced the formation of gas gap, which further influenced the thermal contraction. So the control of velocity of casting above a certain level proved beneficial to enhancing the performance of strip casting and to improving the quality of strip products.

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Three-Layer Clad Strip Casting Using a Vertical Type Tandem Twin Roll Caster

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.773.171 ◽

2018 ◽

Vol 773 ◽

pp. 171-178

Author(s):

Toshio Haga ◽

Kentaro Okamura ◽

Hisaki Warari ◽

Shinichi Nishida

Keyword(s):

Aluminum Alloy ◽

Strip Casting ◽

Tensile Shear ◽

Shear Testing ◽

Roll Speed ◽

Solidification Temperature ◽

Twin Roll Caster ◽

Twin Roll

This paper shows improvements made to a vertical type tandem twin roll caster and the appropriate casting conditions necessary to cast three-layer clad strips, the base strip of which has a lower solidification temperature than the overlay strip. In experiments, 4045 aluminum alloy was used for the base strip and 3003 aluminum alloy was used for the overlay strips. The roll speed was 30 m/min. By connecting the overlay strips to the base strip one at a time and cooling the base strip to between 450 and 530°C after applying the first overlay strip, a sound three-layer clad strip – defined as one in which the interfaces between strips are clear and do not separate during bending-to-failure tests – could be cast. The tensile shear testing between the base and second overlay strip was improved as the base-strip temperature was increased to 450-530°C range.

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