Effects of simulated on line accelerated cooling processing on transformation temperatures and microstructure in microalloyed steels Part 2

Abstract

The effects of three on line accelerated cooling parameters (accelerated cooling start temperature T_A, cooling rate Ṫ, and cooling interrupt temperature T₁) on transformation temperatures and microstructure in a low carbon microalloyed plate steel were studied by laboratory simulations in a quench deformation dilatometer. Varying the on line accelerated cooling parameters changes the austenite condition and transformation path. In general, the transformation path shifts from polygonal ferrite towards bainite with increasing T_A, increasing Ṫ, and decreasing T₁. There is also a corresponding refinement in the microstructure and increase in hardness. In comparison with the laboratory thermomechanical processing treatments, the multipass industrial rolling schedule produces a much more heavily deformed austenite structure than laboratory thermomechanical processing treatments, which would favour high transformation temperatures, fine polygonal ferrite microstructure, and lower hardness.

MST/3425

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References

TAMURA

(ed.): ‘Physical metallurgy of thermomechanical processing of steel and other metals—THERMEC-88’; 1988, Tokyo, Iron and Steel Institute of Japan.

DeARDO

A. J.

(ed.): ‘Processing, microstructure and properties of microalloyed and other modern high strength low alloy steels’; 1992, Warrendale, PA, Iron and Steel Society.

TAYLOR

K. A.

, THOMPSON

S. W.

, and FLETCHER

F. B.

(eds.): ‘Physical metallurgy of direct-quenched steels’; 1993, Warrendale, PA, TMS.

ASFAHANI

and TITHER

(eds.): ‘Low-carbon steels for the 90's’; 1993, Warrendale, PA, TMS.

RUDDLE

G. E.

, VOYZELLE

, BOWKER

J. T.

, and COLLINS

L. E.

: IN ‘Proceedings of 34th mechanical working and steel processing conference’, Vol. 30, 19–30; 1993, Warrendale, PA, Iron and Steel Society.

COLLINS

L. E.

and BARRY

J. R.

: ‘Operation of the MMC quench-deformation dilatometer’, Report MRP/PMRL 84–28, Canmet, Ottawa, Canada, 1984.

PERELOMA

E. V.

and BOYD

J. D.

: Mater. Sci. Technol, 1996, 12, 808–817.

THOMPSON

S. W.

, COLVIN

D. J.

, and KRAUSS

: Metall Trans. A, 1990, A21, 1493–1507.

SMITH

Y. E.

, COLDREN

A. P.

, and CRYDERMAN

R. L.

: in ‘Toward improved ductility and toughness’, 119–142; 1971, Ann Arbor, MI, Climax Molybdenum.

10.

VALDERS

and SELLARS

S. M.

: Mater. Sci. Technol, 1991, 7, 622–631.

11.

ARIETA

F. G.

and SELLARS

S. M.

: in Ref. 4, 101–112.

Effects of simulated on line accelerated cooling processing on transformation temperatures and microstructure in microalloyed steels Part 2—Plate processing

Abstract

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References