Effect of Rolling and Post-Rolling Cooling Strategies on Microstructure and Properties of S355 Structural Steel| Chapter 4 | Engineering Research: Perspectives on Recent Advances Vol. 11

 

Structural rolled steels are the primary products of modern ferrous metallurgy. The S355 grade, according to EN 10025, specifies that steel sheets with 16–40 mm thickness should have a yield tensile strength of not less than 345 MPa and an ultimate tensile strength within the 470–630 MPa interval. These sheets are typically produced using low-carbon Mn-Si steel with micro-additions of carbide/nitride-forming elements (Nb, Ti, V, and Al). Enhancing the mechanical properties of rolled steel using energy-saving processing routes without furnace heating for additional heat treatment is advisable. This study compared the effect on the mechanical properties of structural steel for different processing routes, like conventional hot rolling, normalising, thermo-mechanically controlled processing (TMCP), and TMCP with accelerating cooling (AC) to 550oC or 460oC. The material studied was a 20 mm-thick sheet of S355N grade (EN 10025) made of low-carbon (V+Nb+Al)-micro-alloyed steel. It was found that using different processing routes could increase the mechanical properties of the steel sheets from S355N to S550QL1 grade without additional heat treatment costs. The optimal temperature for finish rolling during normalising rolling is 840oC, enabling the enhancement of steel’s mechanical properties to the E420N grade through grain refinement (ASTM grain size numbers 10–11). Further increase in steel strength was achieved by the application of TMCP. The best combination of strength and low-temperature toughness, equivalent to the S550Q grade, is achieved through TMCP followed by AC to 550oC. This process forms a quasi-polygonal/acicular ferrite structure with minor fractions of dispersed pearlite and martensite-austenite islands, resulting in ductile-brittle transition temperatures of –48.5oC and –36.5oC in the longitudinal and transverse directions, respectively. The contributions of various structural factors to the yield strength and ductile-brittle transition temperature were calculated and correlate well with experimental data. The proposed technologies eliminate the need for normalisation with furnace heating. The practical significance of the results has been demonstrated through reducing production costs connected with natural gas consumption.

 

Author(s) Details

 

Efremenko B.V.
Pryazovskyi State Technical University, 49044 Dnipro, Ukraine.

 

Stavrovskaia V.E.
Pryazovskyi State Technical University, 49044 Dnipro, Ukraine.

 

Sili I.I.
Pryazovskyi State Technical University, 49044 Dnipro, Ukraine.

 

Chabak, Y.G.
Pryazovskyi State Technical University, 49044 Dnipro, Ukraine and Institute of Materials Research, Slovak Academy of Sciences, 04001 Kosice, Slovak Republic.

 

Efremenko V.G.
Pryazovskyi State Technical University, 49044 Dnipro, Ukraine and Institute of Materials Research, Slovak Academy of Sciences, 04001 Kosice, Slovak Republic.

 

Please see the book here :- https://doi.org/10.9734/bpi/erpra/v11/6364

Enhancing the Quality of Rolling and its Allied Practices to Achieve High Productivity, Unmatched Quality, Improved Techno Economic Factors (TEF) and Equipment Reliability in SSP’s Hot Rolling Mill in India | Chapter 8 | Advances and Challenges in Science and Technology Vol. 9

 This stage briefly detail about the enhancement of the feature of rolling and its united practices to achieve extreme productivity, unique quality, upgraded Techno Economic Factors (TEF) and supplies reliability in SSP’s new rolling mill. The logistics and conveyance involved in the without a stain-steel coils complicated further stages of processing distinguished to carbon fortify coils as they are further re-rolled/treated in the cold rolling mill. The Salem Steel Plant (SSP) is operated by Steel Authority of India Limited (SAIL), a state-possessed steel result enterprise in India. In India, SSP is a pioneer in the supplying of stainless fortify coils and sheets with a better breadth. Austenitic, martensitic, ferritic, and low-coat with metallic material stainless brace can be caused at the mill in the form of sheets and coils. The total installed ability is 70,000 tonnes and 3,64,000 tonnes per year in cold rolling mill and vehement rolling mill respectively. Apart from the earlier, SSP boasts the first state-of-the-art without a stain steel blank plant in India for coin or utility blanks. The gird melting shop (SMS), new rolling mill (HRM), and cold rolling mill (CRM) are the three main components of SSP's supplies. The main purpose of Salem Steel Plant's vehement rolling machine search out roll stainless brace slabs. Reheating furnace, formulate mill, steckel mill (finishing mill), below coiler, and roll shop are among the passionate rolling mill's amenities.

Author(s) Details:

K. Muruga Bhoopathy,
Steel Authority of India Limited, Salem Steel Plant, Salem, India.

R. Satish,
Steel Authority of India Limited, Salem Steel Plant, Periyar Institute of Management Studies, Salem, India.

Please see the link here: https://stm.bookpi.org/ACST-V9/article/view/12624