ON THE PROBLEMS OF CONTROL AND REDUCTION OF HIGH-TEMPERATURE LOSS OF STEEL IN HEATING FURNACES

L A Shul’Ts

doi:10.17073/0368-0797-2016-7-470-478

Abstract

The problem of assessment of the steel loss in the thickness of scale is considered for industrial furnaces. The possibilities of different ways to reduce steel oxidation are analyzed. Particular attention is paid to the attendant diffi culties of decrease of steel loss by reducing the oxidant consumption coeffi cient (n). The reality of achievement of substantially nonoxidative steel heating in industrial furnaces at present is shown. The author has highlighted their important technological characteristics: almost molecular mixing of the primary components of combustion (natural gas at n = 0.48 – 0.5), the synchronicity of the burners work and limit n deviation at regulation of primary combustion of fuel Δn ≤ 0,01, the eff ective jet-mechanical throttling of primary gas flow precluding the reverse circulation of the primary products of incomplete combustion from the post-combustion zone to the metal heating zone. Directions of design and work options of forging and rolling furnaces are proposed with the achievement of the relevant indicators for the reduction or complete suppression of steel loss. The problems of internal high-temperature oxidation of silicon of transformer steel are particularly analyzed as well as the nondecarburization heating of ball-bearing steel

Highlights

The problem of assessment of the steel loss in the thickness of scale is considered for industrial furnaces
Particular attention is paid to the attendant difficulties of decrease of steel loss by reducing the oxidant consumption coefficient (n)
The author has highlighted their important technological characteristics: almost molecular mixing of the primary components of combustion, the synchronicity of the burners work and limit n deviation at regulation of primary combustion of fuel Δn ≤ 0,01, the effective jet-mechanical throttling of primary gas flow precluding the reverse circulation of the primary products of incomplete combustion from the post-combustion zone to the metal heating zone

Summary

Introduction

Как показывает анализ, по частным показателям окисления, например по относительному изменению толщины окалины, к примеру, на наиболее доступной верхней грани слябов в отдельных «точках» (участках), можно достаточно точно определить относительное изменение потерь металла при его окислении после тех или иных изменений температурно-временных параметров печи, атмосферного режима, режима работы горелок и пр. Изменение потерь металла от окисления стальных слябов, например, на 1 кг/т или 7,5 % от существующего среднего значения их угара (для ОАО «НЛМК» в прокатных печах) только в зависимости от размеров слябов в соответствии с представленными выше данными соответствует изменению общей толщины окалины при равномерном окислении заготовок со всех сторон от 0,09 – 0,10 до 0,15 – 0,17 мм.

Results

Conclusion