The mould is the core and most critical component of continuous casting machine (CCM). Its performance plays a vital role in determining CCM's production capacity and the billet quality. For a long time, the state of molten steel flow field and mould powder inside the mould can only be predicted and cannot be directly measured. This has led to the mould, the core component of the CCM, being referred to as a "black box". However, the quality problem of billets can only be analyzed by statistics, mechanism and experience, and the effect is not satisfactory. While the installation of thermocouples allows for the measurement of the copper plate temperature of the mould, their temperature measurement stability is poor, and the number of measuring points is limited. As a result, thermocouples can only be used to some extent for predicting the breakout caused by sticking, but it is difficult to be used in other analysis. It can be seen that the mould sensing technology has become a bottleneck in the development of CCM technology.

In 2018, CERI initiated the feasibility study of digital sensing mould technology. The project was officially approved in 2019 with the aim of developing a set of technologies that enable digital sensing and analysis of the mould, achieving quasi-continuous temperature measurement and solve the "pain points" of the industry. By arranging thousands of temperature measuring points, this technology can realize real-time monitoring of the molten steel flow field distribution, temperature distribution, melting condition of mould powder, fluctuation type of molten steel level and change of mould taper inside the mould, find out possible billet surface defects, inform operators of other abnormal casting conditions, solve the "black box" problem of mould, and provide reliable technical support for improving billet quality and standardizing continuous casting production.

After more than four years of research and development, the CERI project team has completed process design and layout, mechanical design and installation, fiber grating sensor packaging and response test, mould temperature measurement reliability test, system software design, database design, interface design and some algorithm models, and 4 patents have been applied for. On July 25, 2022, CERI, in collaboration with Guangxi Liuzhou Steel Group, successfully completed the "First Industrial Test of Digital Sensing Mould Technology in China" at Fangchenggang Base of Liuzhou Steel Group. A total of about 50,000 tons of continuous casting billets were produced during the test. The temperature was measured with a minimum interval of 10mm, and the temperature measurement was accurate. The system software performed reliably, and the test achieved the expected results.

The successful test of CERI's digital sensing mould technology is a major breakthrough in China's continuous casting mould sensing technology. It accurately displays the temperature image inside the mould, perceives the bonding situation during  casting, billet surface cracks, actual shape and fluctuation of meniscus and nozzle blockage, reflects the influence of casting process parameters on casting and its stability, helps operators solve problems and optimize production, protects the casting machine, improves equipment availability, output and quality, and frees up operators' time, allowing them to focus on other important responsibilities. The successful test and subsequent iterative refinement of CERI's digital sensing mould and related analysis technology are of great significance to the continuous casting industry in China.

Test and installation site (temperature measuring points are distributed on the narrow face and broad  face of each mould, and thousands of temperature measuring points can be arranged at most)

System interface (including process parameters, temperature nephograms of each face of mould and billet temperature history plots; the abnormal part in the billet temperature history plot on the right is the impact area of nozzle replacement on billet)

Accurate measurement of thickness of liquid slag layer of mould powder (measured as 15mm and model-calculated as 16mm, and the accuracy of the model calculation is verified)