U.S. patent application number 17/598736 was filed with the patent office on 2022-05-19 for steel alloy, use of such a steel alloy, and component.
The applicant listed for this patent is BAYERISCHE MOTOREN WERKE AKTIENGESELLSCHAFT, Meita Industrial Co. Ltd.. Invention is credited to Clemens Bergmann, Michel Millot.
Application Number | 20220154316 17/598736 |
Document ID | / |
Family ID | 1000006154647 |
Filed Date | 2022-05-19 |
United States Patent
Application |
20220154316 |
Kind Code |
A1 |
Bergmann; Clemens ; et
al. |
May 19, 2022 |
Steel Alloy, Use of Such a Steel Alloy, and Component
Abstract
The invention relates to a steel alloy comprising, in percent by
mass:--0.17 to 0.23 carbon;--1.40 to 1.60 silicon;--0.50 to 0.60
manganese;--up to 0.020 phosphor;--up to 0.020 sulfur;--up to 0.30
chrome;--up to 0.12 molybdenum;--up to 0.80 nickel;--up to 0.30
copper;--up to 0.03 vanadium; the remainder being iron and
incidental impurities.
Inventors: |
Bergmann; Clemens; (Munchen,
DE) ; Millot; Michel; (Heillecourt, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BAYERISCHE MOTOREN WERKE AKTIENGESELLSCHAFT
Meita Industrial Co. Ltd. |
Munchen
Tao Yuan Hsien |
|
DE
TW |
|
|
Family ID: |
1000006154647 |
Appl. No.: |
17/598736 |
Filed: |
March 25, 2020 |
PCT Filed: |
March 25, 2020 |
PCT NO: |
PCT/EP2020/058411 |
371 Date: |
September 27, 2021 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C21D 8/005 20130101;
C21D 2211/005 20130101; C22C 38/04 20130101; C22C 38/002 20130101;
C21D 1/28 20130101; C22C 38/42 20130101; C22C 38/02 20130101; C22C
33/08 20130101; C22C 38/46 20130101; C22C 38/44 20130101; C21D
2211/009 20130101 |
International
Class: |
C22C 38/46 20060101
C22C038/46; C22C 38/02 20060101 C22C038/02; C22C 38/04 20060101
C22C038/04; C22C 38/00 20060101 C22C038/00; C22C 38/42 20060101
C22C038/42; C22C 38/44 20060101 C22C038/44; C21D 8/00 20060101
C21D008/00; C21D 1/28 20060101 C21D001/28; C22C 33/08 20060101
C22C033/08 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 29, 2019 |
EP |
19 166 206.3 |
Claims
1. A steel alloy comprising, in percent by mass: 0.17 to 0.23
carbon; 1.40 to 1.60 silicon; 0.50 to 0.60 manganese; up to 0.020
phosphor; up to 0.020 sulfur; up to 0.30 chrome; up to 0.12
molybdenum; up to 0.80 nickel; up to 0.30 copper; up to 0.03
vanadium; the remainder being iron and incidental impurities.
2. The steel alloy according to claim 1, wherein the steel alloy is
a steel cast alloy.
3. The steel alloy according to claim 2, wherein the steel alloy as
cast has a Brinell hardness of at least 190 HBW 5/750 and/or a
yield point of at least 300 megapascal.
4. A method of manufacturing an article, the method comprising
casting the steel alloy according to claim 1 to form the
article.
5. The method of claim 4, further comprising subjecting the article
to a heat treatment after casting.
6. The method of claim 5, wherein the heat treatment comprises a
normalizing of the article.
7. The method of claim 6, wherein the normalizing is carried out in
a temperature range extending from 900 degrees centigrade to 980
degrees centigrade.
8. The method of claim 5, wherein after the heat treatment the
steel alloy has a tensile strength of at least 560 megapascal
and/or a yield point of at least 370 megapsacal and/or an
elongation at break of at least 20% and/or a Vickers hardness of at
least 180 HV10 and/or a tensile ductility of at least 27 joule.
9. The method of claim 5, wherein the heat treatment creates a
homogeneous perlitic-ferritic structure and during the heat
treatment a carbonization and a decarbonization of the article are
omitted.
10. A component of a vehicle, the component cast from a steel alloy
according to claim 1.
11. The component of claim 10, wherein the component is a body
component for a body in white or an integral body of a vehicle.
12. The component of claim 11, wherein the body component is a
dome.
Description
[0001] The invention relates to a steel alloy, a use of such a
steel alloy, and a component.
[0002] Steel alloys such as, for example, G20Mn5 according to DIN
EN 10293 are well-known from the prior art.
[0003] It is an object of the present invention to provide a steel
alloy, a use of such a steel alloy, as well as a component so that
the component can be manufactured from said steel alloy in a
particular advantageous way.
[0004] This object is solved by a steel alloy having the features
of patent claim 1, by a use having the features of patent claim 4,
and by a component having the features of patent claim 10.
Advantageous embodiments of the invention are indicated in the
dependent claims.
[0005] A first aspect of the present invention relates to a steel
alloy comprising, in percent by mass, 0.17 to 0.23 carbon (C). The
unit or specification "percent by mass" is also referred to as
"percentage by mass", "percentage by weight", "percent by weight",
"weight percent, "weight percentage" or "mass fraction". In the
context of the present invention, the percentage by mass of a
substance within a mixture or an alloy such as the steel alloy
according to the present invention is the ratio of the mass of that
substance to the total mass of the mixture or the alloy
respectively. With respect to an alloy such as the steel alloy
according to the present invention, said substance can be an
alloying element such as carbon. In other words, said carbon is a
substance of the steel alloy according to the present
invention.
[0006] Furthermore, the steel alloy according to the present
invention comprises, in percent by mass, 1.40 to 1.60 silicon (Si),
0.50 to 0.60 manganese (Mn), up to 0.020 phosphor (P), up to 0.020
sulphur (S), up to 0.30 chrome (Cr), up to 0.12 molybdenum (Mo), up
to 0.80 nickel (Ni), up to 0.30 copper (Cu) and up to 0.03 vanadium
(V), the remainder or balance being iron (Fe) and incidental or
unavoidable impurities. This means the carbon, the silicon, the
manganese, the phosphor, the sulphur, the chrome, the molybdenum,
the nickel, the copper and the vanadium are substances, in
particular alloying elements, of the steel alloy according to the
present invention. Moreover, said iron and said impurities are
substances of the steel alloy according to the present invention.
Particularly, said impurities can be conditional of manufacturing.
Preferably, the steel alloy according to the present invention
comprises at least 90 percent by mass, in particular at least 95
percent by mass and preferably at least 95.5 percent by mass of
iron. Preferably, the steel alloy according to the present
invention comprises at least 95.78 percent by mass of iron. In
other words, preferably, the steel alloy comprises a mass fraction
of at least 90 percent, in particular at least 95 percent,
preferably oat least 95.5 percent and preferably at least 95.78
percent of iron, the remainder being incidental or unavoidable or
inevitable impurities.
[0007] It has surprisingly been found that the steel alloy
according to the present invention can be processed, in particular
cast, in a particular advantageous way so that components can be
made of the steel alloy according to the present invention in a
particular advantageous, time- and cost efficient way. It has
particularly been found that silicon, in particular its mass
fraction or percentage by mass according to the present invention,
helps create a particularly good flowability of a molten mass made
from the steel alloy according to the present invention. Moreover,
the mass fraction of silicon according to the present invention
helps realize an advantageously low solidus temperature.
Furthermore, it has been found that manganese and its mass fraction
according to the present invention help avoid an excessive or
unwished reactivity, in particular during processing the steel
alloy.
[0008] In a particular advantageous embodiment of the invention,
the steel alloy according to the present invention is a steel cast
alloy. It has been found that the steel alloy according to the
present invention can be cast in a particular advantageous way due
to said substances and their respective mass fractions. In other
words, the steel alloy according to the present invention can be
processed particular advantageously by casting.
[0009] In a further advantageous embodiment of the invention, the
steel alloy as cast has a Brinell hardness of at least 190 HBW
5/750 and/or a yield point (R.sub.p0.2) of at least 300 megapascal
(N/mm.sup.2). Thus, particular advantageous characteristics of the
steel alloy and, thus, a component made from the steel alloy can be
realized.
[0010] A second aspect of the present invention relates to a use or
usage of the steel alloy according to the present invention,
wherein at least one component is made from the steel alloy, in
particular by casting, i.e. by a casting method or a casting
process. In other words, the second aspect of the present invention
relates to a method for manufacturing at least one component. In
said method the component is manufactured or made from the steel
alloy according to the present invention. Preferably, in said
method, the component is made from the steel alloy by casting, i.e.
by a casting method or a casting process. Thus, the component can
be made in a particular easy and time- and cost-efficient way. In
particular, a particularly low wall thickness of the component can
be realized by manufacturing the component from the steel alloy
according to the present invention. Advantages and advantageous
embodiments of the first aspect of the present invention are to be
regarded as advantages and advantageous embodiments of the second
aspect of the present invention and vice versa.
[0011] In a particularly advantageous embodiment of the invention,
the component is subjected to a heat treatment after the casting.
For example, the component is subjected to at least or exactly one
heat treatment after the casting. Thus, particular advantageous
characteristics of the component can be realized.
[0012] In a further advantageous embodiment of the invention, the
heat treatment comprises a normalizing of the component.
Preferably, the heat treatment is a normalizing of the
component.
[0013] In order to realize particularly advantageous
characteristics of the component, in a further embodiment, the
normalizing is carried out in a temperature range extending from
900 degrees centigrade to 980 degrees centigrade.
[0014] Preferably, after the heat treatment the steel alloy has a
tensile strength (R.sub.m) of at least 560 megapascal and/or a
yield point (R.sub.p0.2) of at least 370 megapascal and/or an
elongation at break (A.sub.5.65) of at least 20% and/or a Vickers
hardness of at least 180 HV10 and/or a viscosity or ductility (KV)
of at least 27 joule, wherein the ductility has been or can be
determined by an impact test. Said tensile strength, said yield
point, said elongation at break, said ductility and said Vickers
hardness as well as said Brinell hardness are mechanical
characteristics or properties of the steel alloy or the component
respectively, wherein said properties and their mentioned
characteristic values have been or can be determined according to
DIN EN ISO 6892-1, in particular by means of a tensile test
according to DIN EN ISO 6892-1. Particularly, said properties and
their mentioned characteristic values have been or can be
determined by means of a sample or probe which can be taken or
drawn according to DIN EN ISO 377. The probe or sample is also
referred to as a specimen. If possible, the specimen type E
according to DIN 50125 should be chosen. Particularly, the
standards, in particular the DIN EN standards mentioned herein are
or have been valid on Jun. 29, 2017.
[0015] In order to realize particularly advantageous
characteristics of the steel alloy or the component respectively,
in a further advantageous embodiment of the invention, a
homogeneous perlitic-ferritic structure or micro structure is
created by the heat treatment, wherein during the heat treatment, a
carbonization and a decarbonisation of the component or steel alloy
respectively are omitted.
[0016] A third aspect of the present invention relates to a
component which is, preferably, a cast component. Said component is
made from the steel alloy according to the invention, i.e. the
steel alloy according to the first aspect of the present invention.
Preferably, the component is manufactured by means of said use or
method for manufacturing the component. Advantages and advantageous
embodiments of the first and second aspects of the present
invention are to be regarded as advantages and advantageous
embodiments of the third aspect of the present invention and vice
versa.
[0017] Preferably, the component is a body component for a body in
white or an integral body of a vehicle, in particular a passenger
vehicle. The body in white or the integral body are also referred
to as a self-supporting body, body work or shell. Preferably, the
body component is a dome such as a suspension-strut dome. In this
regard, the dome has a particularly low wall thickness which can be
realized by using the steel alloy according to the present
invention.
[0018] Further details of the invention derive from the following
description of preferred embodiments as well as from the drawings.
The drawings show in:
[0019] FIG. 1 part of a schematic and perspective view of a
component according to the present invention;
[0020] FIG. 2 part of a further schematic and perspective view of
the component; and
[0021] FIG. 3 a flow diagram illustrating a method for
manufacturing the component.
[0022] In the figures the same elements or elements having the same
functions are indicated by the same reference signs.
[0023] FIGS. 1 and 2 show a component 1 for a vehicle such as a car
or an automobile. In particular, said vehicle is a passenger
vehicle having, in its completely assembled state, a body in white
which is also referred to as a body, an integral body, a
self-supporting body, a bodywork or a shell. In this regard, the
component 1 is a body component of the body in white. Particularly,
the component 1 is a dome in a form of a suspension-strut dome of
the body in white. The component 1 has a particularly low wall
thickness. Moreover, the component 1 has a rib structure 2
stiffening the component 1. Moreover, preferably, the component 1
is formed in one piece. In other words, the component is integrally
formed. As can be seen from FIGS. 1 and 2, the component 1 has a
recess 3 which is, preferably, a through opening. For example, a
spring and/or damper element such as a suspension-strut can be
supported on the component 1 in the vertical direction of the
vehicle upwardly. Alternatively or additionally, the spring and/or
damper element can be arranged partially in the recess 3.
[0024] In order to manufacture the component 1 in a particular easy
and time- and cost-efficient way the component 1 is made from a
steel alloy by casting, i.e. by a casting method. Said steel alloy
is a steel cast alloy which can be processed by casting in a
particularly easy and time- and cost-efficient way. Said steel
alloy comprises at least the following substances, given in mass
fractions in the unit %: [0025] 0.17 to 0.23 carbon (C) [0026] 1.40
to 1.60 silicon (Si) [0027] 0.50 to 0.60 manganese (Mn) [0028] up
to 0.020 phosphor (P) [0029] up to 0.020 sulphur (S) [0030] up to
0.30 chrome (Cr) [0031] up to 0.12 molybdenum (Mo) [0032] up to
0.80 nickel (Ni) [0033] up to 0.30 copper (Cu) [0034] up to 0.03
vanadium (V) [0035] the remainder or balance being iron (Fe) and
incidental, unavoidable or inevitable impurities.
[0036] This means the steel alloy comprises the afore-mentioned
substances, in percent by mass or percentage by mass. In
particular, due to the mass fractions of silicon and manganese
respectively, the steel alloy can be processed very well, in
particular by casting.
[0037] Preferably, after casting the component 1, the component 1
is subjected to a heat treatment, which is, preferably, a
normalizing of the component 1. The normalizing is also referred to
as a normalization and should be performed in a temperature range
of 900 to 980 degrees centigrade. For example, the component 1 is
normalized in an oven. A temperature and an atmosphere in the oven
during the normalizing should be chosen in a way that a homogeneous
perlitic-ferritic grain structure of the component 1 is
accomplished and neither carbonisation nor decarbonisation of the
component 1 or the steel alloy respectively occurs. This can be
proven by means of a grain structure analysis.
[0038] Preferably, in a state or condition after the heat treatment
and before an optional or possible further heat treatment to which
the component 1 is possibly subjected, the component 1 or the steel
alloy has a tensile strength (TS) of at least 560 megapascal and/or
a yield point or yield strength (YS) of at least 370 megapascal
and/or an elongation at break or a fracture elongation (A.sub.5.65)
of at least 20 percent and/or a tensile ductility or toughness (KV)
of at least 27 joule and/or a Vickers hardness of at least 180
HV10. A measurement to determine said toughness is preferably
carried out according to ISO 148-1:2016 which, preferably, is or
has been valid on Jun. 29, 2017. Alternatively or additionally, a
measurement for determining said hardness is carried out according
to DIN EN ISO 6507-1. Said tensile strength, said yield strength,
said fracture elongation, said toughness and said Vickers hardness
are mechanical properties or mechanical characteristics in
normalized condition of the component 1, i.e. after said
normalizing.
[0039] Preferably, after the casting and after the heat treatment
the component 1 is cleaned, preferably by centrifugal blasting.
Preferably, the component 1 is cleaned by means of airless blast
cleaning after the casting and after the heat treatment.
[0040] FIG. 3 shows a flow diagram illustrating a process or
process sequence which is carried out after the casting and after
the heat treatment and, preferably, after said cleaning of the
component 1. The process sequence shown in FIG. 3 is carried out in
order to realize a particularly high quality of a surface of the,
in particular completely manufactured, component 1.
[0041] In a first step S1 of the process sequence, the component 1
is degreased, preferably by means of an alkaline fluid. In a second
step S2 the component 1 is subjected to a first purging in which,
preferably, the component 1 is purged by means of deionised water.
Preferably, the second step S2 is carried out after the first step
S1. In a third step S3 of the process sequence the component 1 is
subjected to an ultrasonically cleaning in which, preferably, the
component 1 is cleaned by means of the deionised water. Preferably,
the third step S3 is carried out after the second step S2. In a
fourth step S4 of the process sequence the component 1 is subjected
to a first chemical polishing which is preferably carried out after
the third step S3. In the fourth step S4 at least or exactly one
layer having a thickness of 10 to 15 micrometres is abased from the
component 1.
[0042] In a fifth step S5 the component 1 is subjected to a second
chemical polishing. The fifth step S5 is an alternative to the
fourth step S4 so that either the fourth step S4 or the fifth step
S5 is carried out. In the fifth step S5 at least or exactly one
layer having a thickness of 25 to 30 micrometres is abased from the
component 1. Preferably, the fourth or fifth step respectively is
carried out after the third step.
[0043] In a sixth step S6 which is preferably carried out after the
fourth step S4 or the fifth step S5 respectively, the component 1
is subjected to a second purging in which the component 1 is purged
by deionised water. In a seventh step S7 of the process sequence
the component 1 is subjected to an ultrasonically cleaning,
wherein, preferably, the seventh step S7 is carried out after the
sixth step S6. In the seventh step S7, the component 1 is
ultrasonically cleaned by means of deionised water. In an eighth
step S8 of the process sequence the component 1 is subjected to a
pickling which is also referred to as a pickeling. Preferably, by
means of the pickling the component 1 is cleaned. Preferably, the
eighth step S8 is carried out after the seventh step S7.
[0044] In a ninth step S9 of the process sequence the component 1
is subjected to a galvanising process in which the component 1 is
galvanised. Preferably, the ninth step S9 is carried out after the
eighth step S8. In the ninth step S9, the component 1 is furnished
or provided with at least one layer by means of galvanising. Said
layer is made of zinc (Zn) in order to protect the component 1 from
corrosion. Since the galvanising in the ninth step S9 is carried
out after the pickling carried out in the eighth step S8, the layer
adheres particularly advantageously or strongly to the surface of
the component 1. In other words, by means of the pickling carried
out in the eighth step a particularly advantageous surface of the
component 1 can be realized, wherein the layer created in the
galvanising process carried out in the ninth step S9 can adhere
very advantageously and strongly to said surface created by the
pickling.
[0045] In a tenth step S10 of the process sequence the component 1
is provided with a corrosion protection oil, in particular by
spraying. In other words, in particular and preferably, said
corrosion protection oil is sprayed on said zinc layer and, thus,
on a surface formed by said layer which is a zinc layer.
Preferably, the tenth step S10 is carried out after the ninth step
S9.
[0046] Preferably, the component 1, in particular in its completely
manufactured state, has a surface having a surface roughness
fulfilling the following demands: Ra max. 10 micrometres, Rz max.
50 micrometres and Rt max. 75 micrometres. Preferably, said surface
roughness is determined or measured according to DIN EN ISO
4288:1997.
[0047] The ninth step S9 is a coating or coating process which is
also referred to as a galvanic zinc coating or galvanic zinc
coating process, said layer being a zinc layer is a coat or a zinc
coat. The zinc coat is also referred to as a sink coating which is,
preferably, at every position of the component 1 and, thus,
completely closed. Preferably, the layer has a thickness of 7 to 15
micrometres.
LIST OF REFERENCE SIGNS
[0048] 1 component [0049] 2 rip structure [0050] 3 recess [0051] S1
first step [0052] S2 second step [0053] S3 third step [0054] S4
fourth step [0055] S5 fifth step [0056] S6 sixth step [0057] S7
seventh step [0058] S8 eighth step [0059] S9 ninth step [0060] S10
tenth step
* * * * *