Development and Application of Thermo-mechanical Control Process Involving Ultra-fast Cooling Technology in China

Abstract

Thermo-mechanical control process (TMCP) is an important and effective rolling technology for microstructural control to obtain excellent mechanical properties, such as high strength, excellent toughness and other performances, which consists of controlled hot rolling and controlled cooling. RAL laboratory in China has been making efforts to develop ultra-fast cooling (UFC) technology, which is referred as the core technology for New Generation (NG)-TMCP. The ongoing development of UFC technology, with high cooling capacity and uniform cooling control, provides the effective control of cooling paths for a wide range of water-cooled steel strips and plates. Here, the development and characterization of UFC technology are introduced, and advanced cooling system (ADCOS) for the UFC equipment will be elucidated as well. Moreover, the superior mechanical properties can be obtained by inter-pass cooling technology during rolling processing, which is characterized by water-cooling between controlled rolling passes and further reheating due to the internal heat capacity of plate on its own. The resultant theory and technology can achieve resource conservation, energy saving and emission reduction for green products in the manufacturing process for upgrading of steel industry in China. KEY WORDS: thermo-mechanical control process (TMCP); ultra-fast cooling (UFC); advanced cooling system (ADCOS); strip and plate; inter-pass cooling. 2. Research and Development of Ultra-fast Cooling Technology and Equipment 2.1. Historical Review of Ultra-fast Cooling for Steel Strips and Plates Since the end of the last century, CRM, the top steel research institution in Europe, had carried out in-depth studies in ultra-fast cooling process and developed the ultra-fast cooling system for hot-rolled steel strips and

Effect of Solidification and Hot Rolling Processes on Wear Performance of TiC-Reinforced Wear-Resistant Steel

“…The solidification rates decreased with the increase in billet thickness, which affected the microstructure and TiC particles formed in the TiC-reinforced steels. The TiC-reinforced steels were homogenized at 1200 • C for 3 h and then hot rolled by two-stage controlled rolling [30] with two reverse rolling mills and cooled by air to ambient temperature. The 30 mm-thick, 60 mm-thick, and 90 mm-thick billets (sample ID: B30, B60, B90) were hot rolled with a rolling compression ratio of 5 (sample ID: B6, B12, B18) to study the effects of the billet solidification rate on the particles and wear resistance of the TiC-reinforced steels.…”

Effect of (Ti, Mo)_xC Particle Size on Wear Performance of High Titanium Abrasion-resistant Steel

“…The solidification rate directly affected the nucleation and growth rates of the (Ti, Mo) x C particles; thus, it affected the size, shape, and distribution of (Ti, Mo) x C particles in the (Ti, Mo) x C-reinforced steels. The billets were heated to 1 200°C for 2 h for solution treatment, were subsequently hot rolled by two-stage controlled rolling, 37) and were aircooled to room temperature. Different thickness reduction were designed to study the effects of the solidification rate and thickness reduction on the particles and properties of the (Ti, Mo) x C-reinforced steels.…”

Microstructure, Mechanical Properties and Wear Resistance of Low Alloy Abrasion Resistant Martensitic Steel Reinforced with TiC Particles

“…The billets were hot rolled to 12 mm thickness plates by two-stage controlled rolling and ultra-fast (~100°C/s) cooled to room temperature. 26) Then the plates were heat treated through three different process. (1) Direct Quenching: the first plate was reheated to 880°C and hold 20 min, then water quenched to room temperature (as 880Q).…”