During cold rolled production of steel, each change of rolls causes a halt in production and affects the roll' s grinding maintenance and consumption. Consequently,rolls are very critical to the costs of steel produc...During cold rolled production of steel, each change of rolls causes a halt in production and affects the roll' s grinding maintenance and consumption. Consequently,rolls are very critical to the costs of steel production. Besides the rolling accidents, surface quality problems, including inhomogeneous wear and a decrease of the surface roughness of the rolls are other main reasons for outage and a change of the rolls. Therefore, safe rolls, with superior wear resistance and roughness retentivity will be a future trend in the cold rolling steel industry. In this study, the property characteristics and in-service performance of high-speed steel (HSS) cold rolling work rolls at Baosteel are discussed. The results of this study indicate that in-service performance of HSS cold work rolls has an improvement over conventional rolls. Implementation of HSS work rolls will prolong the rolling campaign and improve the rolling stability, thus, the cost of cold rolling production can be better controlled.展开更多
This study analyzes the evolution of carbides in the tempering process of a newly developed semi-high speed steel cold forged roll with nitrogen addition using a transmission electron microscope (TEM) equipped with ...This study analyzes the evolution of carbides in the tempering process of a newly developed semi-high speed steel cold forged roll with nitrogen addition using a transmission electron microscope (TEM) equipped with an energy dispersive X-ray (EDX). The precipitation sequence of the carbides was identified in the entire tempering process and it can be expressed as M3C→M3C + M (C, N)Ⅱ→M( C, N)Ⅱ → M7C3Ⅱ + M23 C6. The secondary hardening in the tempering process was mainly due to the dispersed precipitation of fine M( C, N)n particles. The dissolution of M3 C tempered at high temperatures induced the precipitation and coarsening of M7 C31/ and M23 C6.展开更多
文摘During cold rolled production of steel, each change of rolls causes a halt in production and affects the roll' s grinding maintenance and consumption. Consequently,rolls are very critical to the costs of steel production. Besides the rolling accidents, surface quality problems, including inhomogeneous wear and a decrease of the surface roughness of the rolls are other main reasons for outage and a change of the rolls. Therefore, safe rolls, with superior wear resistance and roughness retentivity will be a future trend in the cold rolling steel industry. In this study, the property characteristics and in-service performance of high-speed steel (HSS) cold rolling work rolls at Baosteel are discussed. The results of this study indicate that in-service performance of HSS cold work rolls has an improvement over conventional rolls. Implementation of HSS work rolls will prolong the rolling campaign and improve the rolling stability, thus, the cost of cold rolling production can be better controlled.
基金supported by the Baosteel Group Corporation Project (R05DSES220)
文摘This study analyzes the evolution of carbides in the tempering process of a newly developed semi-high speed steel cold forged roll with nitrogen addition using a transmission electron microscope (TEM) equipped with an energy dispersive X-ray (EDX). The precipitation sequence of the carbides was identified in the entire tempering process and it can be expressed as M3C→M3C + M (C, N)Ⅱ→M( C, N)Ⅱ → M7C3Ⅱ + M23 C6. The secondary hardening in the tempering process was mainly due to the dispersed precipitation of fine M( C, N)n particles. The dissolution of M3 C tempered at high temperatures induced the precipitation and coarsening of M7 C31/ and M23 C6.