Arvedi ESP Process Permits Direct Production of Pipeline Steels
Jun. 18, 2012
On the ESP line installed by Siemens at Acciaieria Arvedia SpA in Cremona, Italy, ultra-thin hot strip and highly sophisticated steel grades up to X70 in compliance with the API (American Petroleum Institute) standard can be produced without additional fine-tuning adjustments. According to a study by the Italian material research institute CSM (Centro Sviluppo Materiali), the hot strip produced recently meets the applicable requirements for tensile strength, microstructure and transition temperature. Thus, the hot strip produced by the ESP process invented by Arvedi is suitable for applications in the oil and gas industries, even under tough climate conditions.
To test the material properties, CSM chose several six or eight millimeters thick strips that had been produced on Arvedi's ESP line during normal operation and without additional fine tuning. The strips were analyzed for their mechanical properties and their microstructures in relation to the API 5L and ISO 3183:2007 standards.
Both types of strips met the X70 specifications with regard to tensile strength and possessed the required microstructure. The Charpy V-test was also passed successfully. Full plastic deformability of the eight-millimeter strip was retained at temperatures down to -20°C and the temperature in the case of the six millimeter thick coil was even down to -40°C.
These results were achieved during ongoing operation, while development of such products on conventional systems can take up to several years in some cases. In combination with their inherent advantages such as low space and investment requirement, and also low specific conversion costs, ESP systems offer a low-cost alternative to the previously usual production of pipeline grades on heavy plate lines. At the same time, thanks to the "endless" mode of production, the quality of the strip product increases, for example with regard to the geometric properties and homogeneity.
Antonio Guindani, head of Arvedi's quality department, commented, "The material properties now confirmed by CSM are all the more impressive considering that our ESP plant in Cremona is actually designed to produce thin strip. The six millimeter strip examined was produced as usual with an intermediate strip thickness of 19 millimeters." Guindani therefore also sees potential for the future, saying that, "Basically, substantially larger intermediate strip thicknesses can be adjusted with the ESP process. This paves the way for producing clearly larger final thicknesses in the same quality. For quality grades such as X52 and X60, we also consider thicknesses of up to one inch (25.4 millimeters) as being feasible".