A method for controlling the quality of large-section ductile iron melt before furnace

Abstract

The invention relates to the technical field of steel casting and computer signal processing, in particular to a large-section nodular cast iron melt mass stokehole control method. The large-section nodular cast iron melt mass stokehole control method includes that a computer database storing parameters such as sample-cup cooling curves after processing of nodular cast iron melt body and nodular cast iron solidification metallographic structure, chemical components and spheroidizing levels after different soaking time is established by taking overall shape of the solidification period of nodular cast iron melt cooling curves as representation of melt mass under the condition of non-equilibrium solidification of a resin sample cup, the cooling curves closest to the cooling curves, newly measured, of nodular cast iron are inquired through a computer, and rapid evaluation of nodular cast iron melt mass can be realized by taking the cooling curves as the representation of the newly measured cooling curves corresponding to the nodular cast iron melt mass. According to the evaluation result, the spheroidizing levels of the current nodular cast iron melt can be judged, and stoke control of the large-section nodular cast iron melt mass can be realized.

Description

technical field [0001] The invention relates to the technical fields of iron and steel casting and computer signal processing, in particular to a furnace front control method for the quality of a large-section ductile iron melt. Background technique [0002] Thermal analysis is a method to study the solidification process by measuring the cooling curve of the melt under specific solidification conditions, and then analyze and recognize the state of the melt. Under specific sampling (sampling temperature, sampling volume) and cooling conditions, the shape of the solidification curve is determined by the state of the measured melt, and the thermal analysis cooling curve contains information about the state of the melt, such as chemical composition, melt temperature , Inoculation effect, spheroidization effect, trace elements, gas content, inclusions, etc., it is expected to realize the evaluation of the melt state by identifying the relevant information of the cooling curve. ...

AI Technical Summary

Problems solved by technology

However, it is still very difficult to control the production quality of ductile iron castings with thick and large cross-sections, and it is difficult to guarantee the production stability.

Due to the large cross-sectional size of thick and large-section ductile iron castings, large thermal joint modulus, and long solidification time, the solidification and crystallization process is extremely complicated, the control before the furnace is difficult, and the production repeatability is poor. Structural defects such as looseness lead to low mechanical properties, especially elongation, and it is difficult to meet the requirements of use. It is necessary to formulate a very strict production control process to obtain qualified castings.

At the same time, the solidification time of thick and large section ductile iron castings is long, and the solidification process of the attached casting or single casting test block is quite different from that of the casting itself. If no body anatomy analysis is carried out, the solidification structure inside the casting cannot be accurately determined, and there is no effective method. The melt state can be evaluated before casting, and the solidification structure of the casting body can be predicted, which cannot provide a basis for formulating appropriate casting process measures or taking corresponding solidification structure control measures

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