NL1003762C2 - Steel type, steel strip and method of manufacture thereof. - Google Patents

Abstract

Steel in the form of sheet or strip having the above chemical composition, balance Fe and inevitable impurities, wherein 0.4</=B/N</=1.2.

Description

STEEL TYPE, STEEL STRAP AND METHOD OF MANUFACTURE THEREOF

The invention relates to a steel type with excellent deep drawing properties, in particular a packaging steel, as well as a steel strip, a method for the manufacture thereof as well as a use of such a steel type or steel strip. In the context of this application, 5 steel type is understood to mean a cold-rolled, annealed and generally post-rolled steel in sheet or rolled or unrolled hand form, which is made into a (semi) product by a number of deformation operations, for example a beverage can or other object where material deformations must be imposed on the flat starting material for the purpose of the intended shape. For producing a beverage can, for example, a cup is formed from a disk of packaging steel by deep drawing in one or more steps, the walls of which are stretched to give the can thus formed a greater height / content. In particular deep drawing and wall drawing in one step requires a well deformable material that is ideally completely isotropic.

In connection with this and also in the broader context of the continuous striving to improve said steel grades, a particular search was made for a combination of the following properties: high or very high R-value; smaller differences in mechanical properties over the bandwidth in particular, but also over the band length, in technical terms a small spread of the properties "edge / middle" and "across the roll", respectively.

It now appears from experiments that a steel type exhibiting spectacularly better mechanical properties - in a continuous annealed and possibly rolled state - is found when it is manufactured from steel of the following steel composition: 30 1003762.

- 2 -

Element Min * Max * C 10 40

Mn 140 200 P 20 5 S 10

Si 30 N ppm 25

Already as 15 35 B as ppm 8 25 10 Cu 40

Sn 10

Cr 40

Ni 40

Mo 10 15 * in 0.001 wt% unless otherwise stated "so" acid-soluble is furthermore mainly Fe and for the remainder residual elements, 0.4 lb / Ns 1.2. With this composition it is possible to obtain a steel type with an improved deep drawing property level and with a greatly reduced spread of the mechanical properties.

It has been found that for achieving optimum results according to the invention, within the above-indicated limits, the following guiding values can be given: element aim * C 20

Mn 160 30 N ppm 20

Already 25

B so ppm 0.8.N

* in 0.001 wt% unless otherwise stated 35 "so" is acid soluble

Since, according to the invention, better mechanical properties can be obtained, thinner material of thinner than 0.20 mm, preferably thinner than 0.18 mm, 40 can be used for a particular application, which fits in perfectly with the aim of using a lighter weight. for example from a steel beverage container or an automotive part.

The invention is further also embodied in a method of manufacturing a continuous annealed steel strip having excellent deep drawing properties, the steel having a composition: 1003762.

- 3 -

Element Min * Max * C 10 40 IMn 140 200 P 20 S 10

Si 30 N ppm 25 A1 Sun 15 35 B Sun ppm 8 25 10 Cu 40

Sn 10

Cr 40

Ni 40

Mo 10 15 * in 0.001 wt% unless otherwise stated "so" is acid-soluble further, mainly Fe and for the rest residual elements, with 0.4 sB / Ns 1.2, which steel successively undergoes the manufacturing steps: hot rolling comprising rolling at a rolling temperature and rolling at a rolling temperature; pickling; cold rolling; 25 - continuous annealing;

and optionally re-rolling and then preferably with a re-rolling reduction> 0.6 X

It is characterized in that the rolling temperature is selected above 825 ° C and the rolling temperature below 690 eC.

A steel strip with very good deformation properties is hereby obtained. In the event of any re-rolling, a re-roll reduction of more than 0.6 X is preferably given in any case. Preferably, a guiding value of 900 ° C is chosen for the rolling temperature and a guiding value of 35 670 ° C for the winding temperature. This forms the basis for a very easily workable strong steel plate. It is preferred that if the roll-on is carried out according to the invention this is done with a post-roll reduction of 10 -20 X. Due to such a high degree of deformation, a steel type with excellent mechanical properties is obtained.

40 The steel grade according to the invention appears to be ideally suited for use as packaging steel in DWI (DWI - drawn wall-ironed), for example applications in which the packaging steel is coated with an Sn-containing coating. and subsequently subject to 1003764.

- 4 - successively deep drawing and wall stretching as in the manufacture of the sleeve part of a two-piece sleeve.

Due to the good mechanical properties of the steel type, such a can can be made lighter again, with which again the demand for less and less material consumption and weight for packaging and other products is met.

The invention will now be further elucidated on the basis of the results of some experiments. Tables 1, 2 and 3 below show the mechanical properties, chemical analysis and micro-structure of cold-plate sheet (Eng .: black plate) and hot-strip plate according to the invention, with the tested plate parts being taken out from the part of the plate that formed the head in the hot rolling process.

Table 1 Mechanical properties (cold strip plate) ^ B & sa ^ sassa = ss & s ^ sBss = sa = sssaBasBSsssBBSSBSssBaasssBssss ^ BBas ^ = s 15 Middle Edge

Along Oblique Cross Along R-value Measurement 1 1.57 1.68 1.83 1.49

Direction 2 1.58 1.68 1.8 1.49 20 3 1.58 1.8 1.82 1.42

Raided. 1.58 1.72 1.82 1.47

RehCRpl Measurement 1 237 234 236 247 2 238 235 235 247 3 238 235 235 247 25 Average. 238 235 235 247

Rm Measurement 1 360 354 359 358 2 362 354 356 358 3 362 356 358 357

Average. 362 355 357 358 30 R30T Measurement 1 55.9 55.5 2 56.6 55.3 3 _56.6 55.7

Average. 57 56 35 In the table above, R-value means the Lankford coefficient, Reh (Rp) the yield strength in N / mm2, Rm the tensile strength in N / mm2, R30T the hardness according to Rockwell 30T.

The slight difference between the boxed values in one row shows that the mechanical properties across the width of the plate are 1003762.

- 5 - vary little.

Table 2 Chemical analysis (hot strip plate (wbp) and steel loading) [wt. X and wt. ppm] 5 Hot band C Mn Al zo1 P S Nh2 Ntotaai Btotaai B zo1 wbp rand ~ 0.016 0.173 0.028 0.0110.0051 17 8 1 wbp medium 0.016 0.171 0.028 0.011 0.005 1_20_8_1_

Steel load 0.016 0.171 0.023 0.011 0.004 Nv. 3 16 9 Nv. 3

SBS ^ BSSSaBSBBBSS ^ B ^ SSSBSBBBaBSaaSSSBSSaSSSSSSaB ^ BaS

10 1 so - acid soluble 2 Nh - free nitrogen 3 n.v. - not established

Table 3 Microstructure of hot strip plate (wbp) 15 and cold strip plate (kbp)

8SSaSS = SSSSBSSSBB = SBSSS = SSKSSSSSa ^ BBBSS

wbp ASTM Cementite B kbp ASTM Cementite B

Edge 9 2-2-0 Edge 11.5 2-0-0

Mid 9 2-2-0 Mid 11.5 2-0-0 20

Striking is the surprisingly high R-value as well as the small difference in properties per indicated direction, which means along in the rolling direction, obliquely below 45 ° therewith and perpendicular to it.

1003762.

Claims (9)

1. Steel type with excellent deep drawing properties, in particular a packaging steel made from steel of the following steel composition: BSSBSBSSBBBSSBSBSSBBBS ^^ B = SS: SSSSS ^ Element Min * Max * C 10 40 Mn 140 200 P 20 S 10 Si 30 N ppm 25 Al Sun 15 35 B Sun ppm 8 25 Cu 40 Sn 10 Cr 40 Ni 40 Mo 10 * in 0.001 wt. X unless otherwise stated "So" is acid soluble 10 11 ============= ^ ==================== ^ furthermore mainly Fe and residual elements, where 0.4 s B / N <1.2. Steel grade according to claim 1, characterized in that the following guide values are used for the following elements: element align * C 20 Mn 160 N ppm 20 Al so 25 B so ppm 0.8.N * in 0.001 wt. X unless otherwise stated "so" is acid soluble 20 '' Steel grade according to one of the preceding claims, with an R-value higher than 1.5 in the rolled state. Steel strip of a steel grade according to any one of the preceding claims, characterized in that it is thinner than 0.20 mm, preferably thinner than 0.18 mm. 1003762. - 7 - 5 Element Mln * Max * C 10 40 Mn 140 200 P 20 S 10 Si 30 N ppm 25 Al Sun 15 35 B Sun ppm 8 25 Cu 40 Sn 10 Cr 40 Ni 40 Mo 10 * in 0.001% by weight unless otherwise stated " thus, acid-soluble is further predominantly Fe and the remainder 10 with 0.4 s B / N s 1.2, which steel experiences successively the manufacturing steps: hot rolling comprising rolling at a rolling temperature and rolling at a rolling temperature; pickling; 15. cold rolling; continuous annealing; and, if desired, re-rolling and then preferably with a re-rolling reduction> 0.6 X, characterized in that the rolling temperature is selected above 825 eC and the roll-up temperature below 690 ° C. 5. Method for manufacturing a continuous annealed steel strip with excellent deep drawing properties, wherein the steel has a composition: A method according to claim 5, characterized in that if it is post-rolled, this is done with a post-roll reduction of 10 - 20%. 25 Use of a steel type or steel strip according to any one of claims 1 to 5, or a steel strip obtained according to claim 5 or 6, for deep drawing and / or wall stretching applications. Steel strip according to claim 4, or of a steel grade according to any one of claims 1 - 3, or obtained according to claim 5 or 1003762. - 8 - 6, as a starting material for DWI processing. Steel strip according to claim 4, or of a steel grade according to any one of claims 1 to 3, or obtained according to claim 5 or 5, provided with an Sn-containing coating. 1003762.