economy

The Hwanghae Iron and Steel Complex readjusted and repaired the curved plate continuous casting process and began its normal operation last February.

This process is a billet production process based on continuous molten iron injection with a curved drawing system covering from the sprue to the outlet where billets come out.

According to Ri Song Ho, a technical official, the curved plate continuous casting process is an ingot process capable of drastically reducing the consumption of time, labour, power and materials while increasing the rolling yield and, therefore, it enables unrestricted production of steel materials in various kinds and sizes with higher qualities and helps improve the working environment.

However, the complex had not operated the process on a normal basis for over 30 years due to various circumstances.

It was in mid-July last year that the metallic material institute of the Material Science and Technology Faculty of Kim Chaek University of Technology took on the urgent task of solving this problem.

It was not easy for them to grasp the technical steps of the continuous casting process of the complex. It was a huge task to comprehensively examine various complicated systems and confirm rational parameters for nozzles, covering slag and crystallizer in a fresh way.

But the research team could neither back off nor hang back.

That problem had to be solved at any cost in order to revitalize the steel production, the very foundation of the country’s economic development.

They accepted the task out of a patriotic spirit rather than a sense of obligation.

They studied a vast amount of literature on the global trend of continuous casting and, on that basis, calculated reasonable technical specifications suited to the practical conditions. And they established a system capable of fully realizing the automatic control of the overall casting process including the crystallizer, the core part of the continuous casting process, and successfully pushed ahead with the production of parts and their application into various systems.

As a result of the team’s devoted and strenuous research efforts, the first trial continuous casting of molten iron from the 20-ton converter was successfully carried out in a little over two months.

The fact that the continuous caster, which could push out only 10-odd-metre billets at most, was fed with tens of tons of molten iron at once and smoothly drew tens-of-metres-long billets for the first time in decades gave a great pleasure to the workers of the complex. 

The team further intensified their research and put the curved plate continuous casting process on a normal track in seven months and completed it to be able to receive molten iron from not only the 20-ton converter but also the 100-ton electric furnace.

“I realized once again through the researchers of Kim Chaek University of Technology that the key to success in research lies in the degree of patriotism before the level of knowledge,” said Kim Chun Chol, process engineer of the analysis workshop of the Hwanghae Iron and Steel Complex.