UA76347C2 - Method for manufacture of cold-rolled tape made of alloy steel - Google Patents

Abstract

Invention relates to the rolling production. The method for manufacture of cold-rolled tape made of alloy steel includes etching, cold rolling, annealing, tempering and cutting of strip into the tapes. In accordance with invention, the preparation of the rough stock is performed by preliminary annealing of the hot-rolled cylinders prior to etching,additional annealing after etching, two-fold cold rolling, where the first cold rolling is performed with 30-40 % reduction, the second cold rolling - with 40-50 % reduction. Between the first and second rolling the intermediate annealing is achieved. The invention ensures the required plasticity and precision of manufacturing the tape, possibilityto use a flow chart of the production of cold-rolled tape on operating aggregates of the shop of cold rolling without additional costs for modernization of the equipment.

Description

Description of the invention

The invention relates to rolling production and can be used in the production of cold-rolled 2 tape from alloy steel of type 2ОХ4МФБ, used for surfacing rollers and rolls.

There is a known method of producing cold-rolled strip from strong alloy steels with an increased (up to 0.7290) carbon content (IBBGZOHHSA, 7KHNM, 5OHH FA) and low-alloy steels (20X, 15XHYUA, 10YUDA with a titanium content of at least 0.0295). Coming from the hot-rolling mill, the rolls are first processed on the unit for thickening the longitudinal release, at which end the strips are joined by the method of contact butt welding. After 70 unwinding on the NTA to ensure the continuity of etching, the ends of the rolls are connected at the welding complex. Etching of the strip takes place in a solution of hydrochloric acid. The strips are wound up to 12 tons in weight. The etched rolls are sent to the five-cell mill 630, where they are rolled with crimping up to 70-7595. After rolling, the cold-rolled rolls are sent to hood furnaces for heat treatment. After cooling, the annealed rolls are sent to the two-cell rolling and dressing mill 630. On the longitudinal cutting unit of the company (Zundvig) 12, the strip is split into strips of the ordered width, the side edges are trimmed, the metal surface is oiled and the strips are wound into rolls. Magazine "Steel" Mo3, 1997, P.N. Smirnov, V.G. Kuznetsov "Features of cold-rolled strip production", based on the prototype.

However, the use of this method in the conditions of JSC "MMK named after Ilyich" will lead to additional costs for the purchase of equipment for the production of alloy tape.

The task set as the basis of the invention is the development of a technology for the preparation of rolling stock and the production of cold-rolled alloy strip on the existing equipment of the cold-rolling shop of JSC "MMK named after Ilyich" without additional capital costs.

The task is solved by the fact that in the method of manufacturing alloyed cold-rolled strip, which includes the technological scheme of production: pickling, cold rolling, annealing, training and dissolution of strips on c 29 strip, in accordance with the invention, the preparation of the roll is carried out due to the preliminary annealing of hot-rolled Ge) rolls before etching, additional annealing after etching, double cold rolling, where the first cold rolling is carried out with crimping 30-4095, the second cold rolling with crimping 40-5095. Intermediate annealing is carried out between the first and second rolling.

The use of the proposed method of manufacturing cold-rolled alloyed tape ensures - the necessary plasticity and precision of tape production, under the conditions of OJSC "MMK named after Ilyich" allows you to obtain "Its floating tape without additional capital costs.

The claimed method is carried out as follows. She

The hot-rolled rolling stock after hot rolling has a temporary tensile strength of 1400 N/mm2, (Ce)

In order to reduce the strong properties of rolled products, which are set during etching, preliminary annealing of single-strip hot-rolled rolls is done at a temperature of 760 C, as a result of heat treatment, the strength limit of hot-rolled rolls is reduced to 725 N/mm2,

In pickling, hot-rolled alloy strips are set sequentially after carbon strips from St3 steel (all degrees of deoxidation) in order to obtain welding joints with sufficient resistance for the "70" pickling and rolling process. z c Winding of the combined rolls is done in such a way that the doped strip is the outer strip.

In order to obtain uniform properties of the etched strips and heat treatment of the welding joint, additional annealing of two-strip hot-rolled rolls is performed at a temperature of 7602 with a total duration of heating (heating and holding) of 18 hours.

The task during the first rolling of rolls, which consist of StZ3 of all degrees of deoxidation and alloy steel -I type 20HAMPFB with a size of 3.2 x 1080 mm, is carried out in such a way that the first strips of StZ steel (of all degrees of deoxidation) are set for rolling in order to adjust the mill to the required initial thickness. The first rolling

Me is carried out with crimping 30-4095 at a speed of up to 5 m/sec. Manufacturing accuracy in terms of thickness for rolling after 2) the first rolling - in the plus tolerance field of accuracy BT GOST 19904 (0.16 mm).

After intermediate annealing, the second rolling is done with the total pressing of 40-5095 to a thickness of 1.0 mm. Ready-made and cold-rolled strips are rolled into the JSC tolerance field (GOST 19904) of 40.09 mm. "And after cold rolling, the coiled two-strip coils have an inner diameter of 600 mm, an outer diameter of up to 1800 mm. The final annealing and tempering of the strips from alloy steel type 2ОХ4МФБ with a relative compression of up to 0.5-1.595 provides the following level of properties: temporary tear resistance at the level of 545 -655 N/mm7, cold bending - satisfactory, number of bends 17...19, hardness 71-87 NKV.

The division of rolls into strips is done on a dressing machine.

IF) Pretreated rolls made of alloy steel type 20X4MFB are subjected to cutting into a blank of size 1.0 x 328 mm on a longitudinal cutting unit and then into a narrow strip of size 1.0 x 32 mm.

Carrying out in the method of preparation of the roll before etching the preliminary softening annealing, determined by the 60 layout when placing the etched strips from alloy and carbon steel ensures uninterrupted transportation during the etching process of hot-rolled strips from alloy steel type 20ХА4МФБ on the existing equipment of the continuous pickling line Mo1 TЧП.

Additional annealing before rolling helps increase the passability of combined welding joints during cold rolling due to heat treatment of the seam area, which contributes to the stable conduct of the 65 technological process of double cold rolling.

Double cold rolling (with intermediate annealing) with crimping 30-4095 and 40-50905, final annealing and dressing with crimping 0.5-1.5906 provides a strip 1.0 mm thick with maximum thickness tolerances from 40.06 mm to -00.16 mm on a cold rolling condition of 1700.

Cold rolling of alloy strip steel on a five-cell mill 630 and a two-cell training mill 630 facilitates the task of obtaining a strip of the required accuracy group in terms of thickness and with the necessary mechanical properties, but in the conditions of OJSC "MMK named after Ilyich" it is more profitable to obtain a welded strip according to the proposed technological scheme on existing equipment without additional costs (compared to the tape received from other enterprises).

The economic efficiency of the proposed method in comparison with the known ones lies in the real possibility of using the proposed technological scheme for the production of cold-rolled strip from alloyed steel grades in accordance with the requirements of consumers on the existing units of the cold rolling shop without additional costs for the modernization of the equipment. Mastering the production of welded tape expands the assortment and quality possibilities of cold-rolled redistribution and makes the process of restoring rolls and rollers by the welding method cheaper in the slabbing-1150, LITS-1700, UGM, LPC-4500 workshops of OJSC "MMK named after Ilyich".

Claims (1)

The formula of the invention is the method of manufacturing cold-rolled strip from alloy steel, which includes etching, cold rolling, annealing, dressing and cutting the strip into strips, which is characterized by the fact that the preparation of the roll is carried out due to the preliminary annealing of hot-rolled rolls before etching, additional annealing after etching, two-time cold rolling mills, where the first cold rolling is carried out with crimping 30-4095, the second cold rolling - with crimping 40-5095, and intermediate annealing is carried out between the first and second crimping. триигя я " : " " : : povs Official Bulletin "Industrial Property". Book 1 "Inventions, useful models, topographies of integrated microcircuits", 2006, M 7, 15.07.2006. State Department of Intellectual Property of the Ministry of Education and Science of Ukraine. in « (ze) (Se) and - - and? -i (o) (95) sh» what has) 60 b5