Solid-liquid Combination And Solidification Quality Research Of The High Carbon Medium Chromium Alloy Steel/low Carbon And Medium Carbon Carbon Steel

In this paper,the metallurgical combination of two kinds of different property metal was achieved through liquid-solid combined technology and improved the quality of liquid steel solidification.This technology has the important significance for the development of highperformance metal composite materials.Steel rod was inserted in the ingot mould,and realized the metallurgical combination of the two metals by pouring molten steel(the internal diameter of ingot mould is 105 mm,and wall thickness is 40 mm.The steel mandrels use the different diameter 20# steels.The pouring molten steel is high-carbon mediumchromium alloy steel and the pouring temperature is 1620?).The liquid solid bonding temperature field mathematical model was established of high-carbon mediumchromium alloy steel/low carbon steel to calculate the mandrel surface temperature changes with time during solidification of liquid steel.On this basis,two kinds of metal bonding interface after the solidification was observed under the microscope,and determined the interfacial bonding strength,analysis of the interfacial bonding mechanism and the influence factors of the interface binding quality and liquid steel solidification quality.Conclusions were obtained as followed:(1)The mathematic model for the temperature filed of liquid-solid combination of two kinds of metal in mould was built and the changes of the surface temperature of 20# steel rod in different diameters with the time was carried out and its regulation was consistent with the experiment result.(2)The condition to realize the combination of two metal material by the solid-liquid combined technology was that the solid metal surface temperature under the effect of heat transfer of liquid steel was in the temperature field of the two-phase zone of liquid and solid.The process paramenters involved in the combination condition could be calculated quantitatively by the model.(3)The dominant mechanism of two kinds of metal by liquid-solid technology to realize the metallurgical combination was epitaxial crystallization mechanism.(4)Factors influencing the metallurgical combination of two kinds of metal by liquidsolid technology were the surface status of the solid metal,the liquid steel temperature,pouring environment and cooling condition after casting.Experiments showed that solid metal surface after sand blasting treatment,increasing pouring temperature,melting and casting at vacuum condition and cooling slowly after casting were beneficial to improvement of the interface combination quality.(5)The liquid steel solidification temperature field was changed by the application of the solid-liquid combination technology and contributes to the isometric zone broadening.