CN113637831A - Processing technology of SAPH440 high-strength structural steel - Google Patents
Processing technology of SAPH440 high-strength structural steel Download PDFInfo
- Publication number
- CN113637831A CN113637831A CN202110827900.3A CN202110827900A CN113637831A CN 113637831 A CN113637831 A CN 113637831A CN 202110827900 A CN202110827900 A CN 202110827900A CN 113637831 A CN113637831 A CN 113637831A
- Authority
- CN
- China
- Prior art keywords
- coil
- rolled
- saph440
- annealing furnace
- hot
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 229910000746 Structural steel Inorganic materials 0.000 title claims abstract description 21
- 238000012545 processing Methods 0.000 title claims abstract description 20
- 238000005516 engineering process Methods 0.000 title claims abstract description 13
- 238000000137 annealing Methods 0.000 claims abstract description 52
- 238000005096 rolling process Methods 0.000 claims abstract description 27
- 238000005554 pickling Methods 0.000 claims abstract description 20
- 238000000034 method Methods 0.000 claims abstract description 16
- 239000002253 acid Substances 0.000 claims abstract description 11
- 238000004806 packaging method and process Methods 0.000 claims abstract description 8
- 238000005406 washing Methods 0.000 claims abstract description 7
- 239000000126 substance Substances 0.000 claims abstract description 6
- 238000010438 heat treatment Methods 0.000 claims description 21
- 238000001816 cooling Methods 0.000 claims description 16
- 229910000831 Steel Inorganic materials 0.000 claims description 13
- 239000010959 steel Substances 0.000 claims description 13
- 230000008569 process Effects 0.000 claims description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 5
- 239000007788 liquid Substances 0.000 claims description 4
- 229910052799 carbon Inorganic materials 0.000 claims description 3
- 238000007599 discharging Methods 0.000 claims description 3
- 238000012360 testing method Methods 0.000 claims description 3
- 238000004140 cleaning Methods 0.000 claims description 2
- 238000002161 passivation Methods 0.000 claims 3
- 238000006386 neutralization reaction Methods 0.000 claims 2
- 239000000463 material Substances 0.000 abstract description 35
- 238000010008 shearing Methods 0.000 abstract description 16
- 238000001514 detection method Methods 0.000 abstract description 7
- 230000009286 beneficial effect Effects 0.000 abstract description 6
- 238000005098 hot rolling Methods 0.000 abstract description 4
- 239000002994 raw material Substances 0.000 abstract description 4
- 239000013072 incoming material Substances 0.000 abstract 1
- 238000004519 manufacturing process Methods 0.000 description 14
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 5
- 238000005452 bending Methods 0.000 description 3
- 206010039509 Scab Diseases 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 238000005261 decarburization Methods 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 238000007373 indentation Methods 0.000 description 2
- 230000003472 neutralizing effect Effects 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 229910001339 C alloy Inorganic materials 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 230000002159 abnormal effect Effects 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 238000010923 batch production Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000005097 cold rolling Methods 0.000 description 1
- 238000007590 electrostatic spraying Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 230000009191 jumping Effects 0.000 description 1
- 239000010410 layer Substances 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910001562 pearlite Inorganic materials 0.000 description 1
- 238000010587 phase diagram Methods 0.000 description 1
- 238000005482 strain hardening Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0205—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips of ferrous alloys
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
- B21C37/00—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape
- B21C37/02—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape of sheets
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/26—Methods of annealing
- C21D1/30—Stress-relieving
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
- C21D8/0226—Hot rolling
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
- C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
- C23G1/02—Cleaning or pickling metallic material with solutions or molten salts with acid solutions
- C23G1/08—Iron or steel
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Crystallography & Structural Chemistry (AREA)
- Thermal Sciences (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Child & Adolescent Psychology (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Heat Treatment Of Sheet Steel (AREA)
Abstract
The invention relates to a processing technology of SAPH440 high-strength structural steel, which comprises the following steps: selecting a hot-rolled coil with the SAPH440 mark, and arranging incoming material detection; carrying out primary longitudinal shearing and splitting on the qualified hot-rolled large-coil raw material; pickling the longitudinally-sheared and stripped hot-rolled coil to obtain a pickled coil; finely flattening the acid-washed coil plate to obtain a finely-rolled coil plate; loading the finish-rolled coil into a cover type annealing cover for stress relief annealing; the annealed coil plate after stress relief is subjected to secondary longitudinal shearing slitting through a small slitting machine, and a slitting coil plate is prepared; and packaging and warehousing, and packaging the split rolled plates by using a packaging machine. The invention has the beneficial effects that: the method selects the special fine grain structural steel hot rolling blank with high strength chemical components as a raw material, removes the oxide skin on the surface of the hot rolling material after acid washing, is beneficial to smooth operation of subsequent rolling procedures, and avoids the poor appearance problems of scaling, pits, pocking marks and the like caused by the pressing-in of the oxide skin in the rolling process.
Description
Technical Field
The invention relates to the technical field of strip steel production and processing, in particular to a processing technology of SAPH440 high-strength structural steel.
Background
It is known that strip steel is a narrow and long steel sheet produced to suit the needs of different industrial sectors. The width of the glass is generally within 300mm, but with economic development, the width is not limited. The steel strip is supplied in a coiled manner, has the advantages of high dimensional precision, good surface quality, convenient processing, material saving and the like, and is widely used for producing blanks of cold-formed steel, bicycle frames, rims, clamps, gaskets, spring pieces, saw blades, blades and automobile fine blanking parts.
With the development of the automobile industry, higher requirements are provided for some important structural parts, particularly, the carbon structural steel and the high, medium and low carbon alloy steel cannot meet the requirements on higher tensile strength on the premise of ensuring the light weight of parts, and are also suitable for fine die bending and cold forming without cracking, either the yield ratio does not meet the standard as the structural part is unsafe, or the strength does not meet the standard and the thickness of the part needs to be increased, so that the weight of the parts is greatly increased, and the requirements on vehicle light weight are not met. However, in order to meet the requirement in the industry, thick hot rolling raw materials are often adopted, the internal structure of the material is changed through large rolling reduction, and an annealing process is assisted to meet the requirement that the finished material is suitable for fine blanking production. However, domestic and foreign high-strength yield series steel grades basically belong to fine grain structural steel, internal grains are seriously crushed after rolling under high reduction, abnormal poor coarse grain structures are often generated after annealing, and the production of fine-blanking parts is very unfavorable. Therefore, a method for processing a high-strength structural steel for cold forming is produced.
Disclosure of Invention
The technical problem to be solved by the invention is to provide a high-strength structural steel processing technology which can stabilize the size of a fine blanking part, improve the product quality, has high tensile strength, certain hardness and heat treatment process characteristics, reduces the weight of a structural part and is suitable for bending production of a fine blanking die.
The technical scheme for solving the technical problems is as follows: a processing technology of SAPH440 high-strength structural steel comprises the following steps:
step one, selecting a hot-rolled coil with the SAPH440 mark;
step two, slitting for the first time;
step three, acid washing;
step four, finish rolling;
step five, stress relief annealing;
sixth, slitting for the second time;
and step seven, packaging and warehousing.
The invention has the beneficial effects that: the first longitudinal shearing strip-splitting hot rolled coil is pickled before rolling, and the pickling process removes the oxide scales on the surface layer of the hot rolled material, so that the quality problem that the oxide scales are pressed into a material matrix in subsequent rolling is avoided. The method has the advantages that a slight finish rolling mode is adopted in the rolling process, so that the cold rolling deformation of the material is small, the mechanical property of the hot rolled material is ensured, the size precision of the cold rolled material is realized, the tensile strength, the yield strength and the elongation property of the finished material meet the standard requirements of high-strength structural steel, the production process is simplified, the efficiency is greatly improved, the stress-relief annealing after rolling is increased, the obtained finished material meets the requirements of the batch production process of the fine stamping structural parts, the quality problems of forming, bending cracking and the like caused by cold work hardening are avoided, and the production yield of the product is improved.
On the basis of the technical scheme, the invention can be further improved as follows.
Further: the hot-rolled coil comprises the following chemical components according to Bao steel Q/BQB310-2019 enterprise standard: 0.11-0.16 of C, Si:0.15-0.30, Mn: 1.0-1.4.
The adoption of the further beneficial effects is as follows: the toughness of parts of the material without heat treatment and the hardenability of the parts needing heat treatment on the parts of the terminal customer are ensured.
Further, when pickling is carried out, the negative difference of the thicknesses of the stress-relief annealing coiled plate before and after pickling is smaller than 0.15mm, the number of the pickling grooves is two, the number of the passivating grooves is one, the number of the neutralizing grooves is one, the pickling concentrations of the two pickling grooves are respectively 18% -22% and 15% -18%, the acid liquid levels in the two pickling grooves are 380 mm-420 mm, the acid liquid temperature is 50-70 ℃, the pH value of the neutralizing groove is 11-13, the pH value of the passivating groove is 7-8, the temperature value of the passivating groove is 40-50 ℃, and the cleaning speed of a pickling production line is 5-15 m/min.
The adoption of the further beneficial effects is as follows: the oxide skin generated in the controlled cooling and controlled rolling process of the hot-rolled strip-divided coiled plate can be effectively removed, and the influence on subsequent deep processing is avoided.
Further: and (3) during stress relief annealing:
firstly, heating an annealing furnace to 200 ℃ at full speed, and preserving heat for a preset time;
secondly, heating the annealing furnace to 420 ℃ within 5h, and preserving the heat for a preset time;
thirdly, heating the annealing furnace to 650 ℃ within 8h, and preserving heat for a preset time;
fourthly, cooling to 610 ℃ along with the furnace, and preserving heat for 2 hours;
fifthly, heating the annealing furnace to 650 ℃ at full speed, and preserving heat for 4 hours;
sixthly, cooling to 610 ℃ along with the furnace, and preserving heat for 2 hours;
seventhly, heating the annealing furnace to 650 ℃ at full speed, and preserving heat for 4 hours;
eighthly, cooling to 610 ℃ along with the furnace, and preserving heat for 2 hours;
ninth, heating the annealing furnace to 650 ℃ at full speed, and preserving heat for 4 hours;
tenth, cover changing and air cooling are carried out on the annealing furnace, and the temperature of the annealing furnace is reduced to 320 ℃;
eleventh, after the temperature of the annealing furnace is reduced to 320 ℃, reducing the temperature of the annealing furnace to 100 ℃ in a water cooling mode;
and finally, discharging the coil out of the furnace to obtain the stress-relief annealed coil.
Furthermore, before the second longitudinal shearing and splitting, a universal testing machine and a hardness tester are required to be used for detecting the mechanical property and the hardness of the annealed coil, and the qualified range of the mechanical property of the material is as follows: the tensile strength is more than or equal to 440MPa, the yield strength is more than or equal to 305MPa, and the elongation is more than or equal to 33 percent; the qualified range of the hardness value is 75HRB to 90 HRB; and putting the annealed coils with qualified mechanical properties and hardness on a small slitting machine.
The adoption of the further beneficial effects is as follows: parameter values in the production process can be adjusted in time according to the detection data, whether sequence conversion production is carried out or not is judged in advance, and the quality characteristic of finished products is ensured.
Drawings
FIG. 1 is a characteristic curve of a material stress-relief annealing process in the processing technology of the SAPH440 high-strength structural steel according to the invention;
FIG. 2 is a mechanical property curve of the product material in the SAPH440 high-strength structural steel processing technology of the invention;
FIG. 3 is a reference metallographic phase diagram of metallographic phase detection of a product material in the processing technology of SAPH440 high-strength structural steel according to the present invention.
Detailed Description
The principles and features of this invention are described below in conjunction with the following drawings, which are set forth by way of illustration only and are not intended to limit the scope of the invention.
A processing technology of SAPH440 high-strength structural steel comprises the following steps:
step one, preparing raw materials, and selecting a hot-rolled coil plate with the SAPH440 mark, wherein the requirements of chemical components of the SAPH440 hot-rolled coil plate are as follows: 0.11-0.16% of C, 0.15-0.30% of Si, 1.0-1.40% of Mn, P: less than or equal to 0.025, S: not more than 0.020 and not less than 0.010 percent of Alt; the requirements of the metallographic phase of the hot rolled coil of SAPH440 are as follows: ferrite plus pearlite structure and a decarburized layer, wherein when the thickness is greater than 5mm, the allowable decarburization is less than or equal to 1% t, wherein t is the thickness of a hot rolled steel plate, when the thickness is less than or equal to 5mm, the allowable decarburization is less than 50 μm, the banded structure is less than 2 grade, the fine system of inclusions is less than 2 grade, in the embodiment, the thickness of a hot rolled coil plate with the mark of SAPH440 is 3.95mm, and the thickness of a finished product material is 3.8 +/-0.07 mm;
step two, slitting and splitting for the first time, and transferring the hot-rolled coiled plate prepared in the step one to a first large slitting production line through a hoisting device to perform slitting and splitting for the first time, wherein in order to facilitate subsequent process processing, the width direction of the hot-rolled coiled plate is reserved with a margin of about 0.5mm during slitting, and the thickness allowable deviation of the hot-rolled coiled plate meets the specification of GB/T709 and the convexity requirement: the thickness is less than or equal to 3.0mm, and the convexity is less than or equal to 40 μm; the thickness is 3mm to 8.0mm, the convexity is less than or equal to 60 micrometers, the thickness is more than 8.0mm, the convexity is less than or equal to 100 micrometers, bubbles, cracks, scabs, warping, pulling cracks and inclusions cannot be formed on the surface of the hot-rolled coil, the hot-rolled coil cannot be layered, and slight pockmarks, local deep pockmarks, small bubbles, slight scratches and roller indentations within a half of the thickness tolerance range are allowed on the surface; the edge of the hot-rolled coil is neat and has no saw-tooth shape, and the jumping of the reference end face of the blade is less than or equal to 0.06mm during longitudinal shearing;
step three, acid washing, namely transferring the coiled plate obtained by slitting through the first longitudinal shearing to an acid washing production line through a hoisting device for acid washing to obtain an acid-washed coiled plate;
step four, finish rolling, namely transferring the acid-washed coiled plate obtained after acid washing to a rolling mill production line through a hoisting device for finish rolling, and preparing a finish-rolled coiled plate, wherein the thickness of the finish-rolled coiled plate is 3.8 +/-0.07 mm; the pickling coil is subjected to fine rolling, only slight fine flattening is arranged, so that the rolling amount of the pickling coil is reduced as much as possible on the premise of ensuring the required thickness precision of a finished product, the material subjected to fine rolling has the comprehensive mechanical property of the hot rolling original parent metal, the dimensional precision of the material is maintained, and the mechanical property of the material meets the standard requirement of high-strength structural steel; during finish rolling, the thickness size of the material is controlled at the upper limit, the leveling quantity of a hot rolled blank is reduced as much as possible, the dimensional precision of the material is kept, and meanwhile, the mechanical property of the material meets the standard requirement of high-strength structural steel;
step five, stress relief annealing, namely, enabling the rolled plate obtained after finish rolling to enter a bell-type annealing furnace through a traveling crane and a special lifting appliance device, and performing stress relief annealing at 650 ℃/4H to obtain an annealed rolled plate; a stress relief annealing process is arranged before secondary longitudinal shearing and splitting after the fine rolling, so that the internal stress after the material rolling is eliminated, and the buckling deformation and the dimensional stability of the subsequent punched parts are improved on the premise of ensuring that the mechanical property of the material meets the requirement; when stress is removed, the annealing process temperature of the material is set below the critical phase transition temperature so as to eliminate the internal stress concentration during fine leveling, so that the material has better extension property, the internal stress of the rolling process is fully released while the original fine-grained steel metallographic structure of the material is kept, and conditions are created for the stable size of the subsequent fine-punched part,
and (3) during stress relief annealing:
firstly, heating an annealing furnace to 200 ℃ at full speed, and preserving heat for a preset time;
secondly, heating the annealing furnace to 420 ℃ within 5h, and preserving the heat for a preset time;
thirdly, heating the annealing furnace to 650 ℃ within 8h, and preserving heat for a preset time;
fourthly, cooling to 610 ℃ along with the furnace, and preserving heat for 2 hours;
fifthly, heating the annealing furnace to 650 ℃ at full speed, and preserving heat for 4 hours;
sixthly, cooling to 610 ℃ along with the furnace, and preserving heat for 2 hours;
seventhly, heating the annealing furnace to 650 ℃ at full speed, and preserving heat for 4 hours;
eighthly, cooling to 610 ℃ along with the furnace, and preserving heat for 2 hours;
ninth, heating the annealing furnace to 650 ℃ at full speed, and preserving heat for 4 hours;
tenth, cover changing and air cooling are carried out on the annealing furnace, and the temperature of the annealing furnace is reduced to 320 ℃;
eleventh, after the temperature of the annealing furnace is reduced to 320 ℃, reducing the temperature of the annealing furnace to 100 ℃ in a water cooling mode;
finally, discharging to obtain a stress-relief annealed coil, wherein the stress-relief annealed coil is shown in figure 1;
sixth, slitting and splitting for the second time, transferring the annealed coil obtained after stress relief annealing to a small slitting machine through a hoisting device for slitting and splitting for the second time, and preparing a split coil;
and seventhly, packaging and warehousing, and packaging the split coiled plates obtained after the secondary longitudinal shearing and splitting by using a packaging machine.
In the invention, specific operation flows of first longitudinal shearing and splitting, pickling, finish rolling, stress relief annealing and second longitudinal shearing and splitting are set according to the processing technological characteristics of the steel plate for cold forming, so that the stability of the quality of a produced product is effectively controlled, when the thickness of a cold-rolled plate changes, the thickness of a hot-rolled coil plate is selected to be adjusted timely, but the operation flows of the first longitudinal shearing and splitting, pickling, finish rolling, stress relief annealing and the second longitudinal shearing and splitting in the manufacturing process are indispensable for a cold-rolled material finished product of the material of the brand.
In the whole production process of the strip steel, secondary detection is required, wherein the feeding inspection is performed for one time, namely, the thickness and the width of the selected hot rolled material are ensured to meet the requirements of a planned finished product, and the chemical composition, the mechanical property and the tissue structure of the material must meet the requirements of the SAPH440 specific hot rolled material technical protocol standard. After the second material is finely leveled, a stress relief annealing process must be arranged before the second longitudinal shearing splitting, and the annealing process curve refers to fig. 1. Detecting the mechanical property and the hardness of the finish-rolled coil after the coil is taken out of the furnace by a universal testing machine and a hardness meter, wherein the mechanical property of the material is required to meet the requirements specified by the Q/BQB310-2019 standard, and the qualified range of the hardness value is 75HRB to 90HRB according to the reference figure 2; and performing metallographic detection on the finish-rolled coil with qualified mechanical property and hardness value, and putting the finish-rolled coil with qualified metallographic detection on a small slitting machine, wherein the metallographic detection refers to the specification of GB/T13299 standard, and is shown in figure 3.
When the first longitudinal shearing and splitting are carried out, bubbles, cracks, scabs, warping, pulling cracks and inclusions cannot exist on the surface of the hot-rolled coil, the hot-rolled coil cannot be layered, and slight pits, local deep pits, small bubbles, slight scratches and roller indentations within a half of the thickness tolerance range are allowed on the surface; the edge of the hot-rolled coil is neat and has no saw tooth, and the reference end face runout of the blade is less than or equal to 0.06 mm.
The surface of the rolled coil obtained in the rolling process has no warping, pits, pockmarks, yellow rust, water rust, scratches and straight plate shape; side part: no napping and broken edges. The surface of the split rolled plate obtained by the second longitudinal shearing splitting has no warping, pockmarks, pits, water rust, scratches, yellow rust, impression, flat and straight plate shape and no broken edges at the edge part; and when the second longitudinal shearing slitting is carried out, the strip-dividing rolling plate needs to be coated with anti-rust oil by electrostatic spraying.
Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.
Claims (5)
1. A processing technology of SAPH440 high-strength structural steel is characterized by comprising the following steps:
step one, selecting a hot-rolled coil with the SAPH440 mark;
step two, slitting for the first time;
step three, acid washing;
step four, finish rolling;
step five, stress relief annealing;
sixth, slitting for the second time;
and step seven, packaging and warehousing.
2. The processing technology of the SAPH440 high-strength structural steel according to claim 1, wherein the chemical components of the hot-rolled coils are according to Bao steel Q/BQB310-2019 enterprise standard, and the chemical components in the hot-rolled coils are as follows: 0.11-0.16 of C, Si:0.15-0.30, Mn: 1.0-1.4.
3. The process of claim 1, wherein during pickling, the negative difference between the thicknesses of the stress-relieved annealed coil before and after pickling is less than 0.15mm, the number of pickling tanks is two, the number of passivation tanks is one, the number of neutralization tanks is one, the pickling concentrations of the two pickling tanks are respectively 18 to 22 percent and 15 to 18 percent, the acid liquid levels in the two pickling tanks are 380 to 420mm, the acid liquid temperature is 50 to 70 ℃, the pH value of the neutralization tank is 11 to 13, the pH value of the passivation tank is 7 to 8, the temperature value of the passivation tank is 40 to 50 ℃, and the cleaning speed of the pickling line is 5 to 15 m/min.
4. The processing technique of SAPH440 high strength structural steel according to claim 1, wherein during stress relief annealing:
firstly, heating an annealing furnace to 200 ℃ at full speed, and preserving heat for a preset time;
secondly, heating the annealing furnace to 420 ℃ within 5h, and preserving the heat for a preset time;
thirdly, heating the annealing furnace to 650 ℃ within 8h, and preserving heat for a preset time;
fourthly, cooling to 610 ℃ along with the furnace, and preserving heat for 2 hours;
fifthly, heating the annealing furnace to 650 ℃ at full speed, and preserving heat for 4 hours;
sixthly, cooling to 610 ℃ along with the furnace, and preserving heat for 2 hours;
seventhly, heating the annealing furnace to 650 ℃ at full speed, and preserving heat for 4 hours;
eighthly, cooling to 610 ℃ along with the furnace, and preserving heat for 2 hours;
ninth, heating the annealing furnace to 650 ℃ at full speed, and preserving heat for 4 hours;
tenth, cover changing and air cooling are carried out on the annealing furnace, and the temperature of the annealing furnace is reduced to 320 ℃;
eleventh, after the temperature of the annealing furnace is reduced to 320 ℃, reducing the temperature of the annealing furnace to 100 ℃ in a water cooling mode;
and finally, discharging the coil out of the furnace to obtain the stress-relief annealed coil.
5. The processing technology of the SAPH440 high-strength structural steel as claimed in claim 4, wherein before the second slitting, a universal tester and a hardness tester are used to test the mechanical properties and hardness of the finish-rolled sheet, and the qualified range of the mechanical properties of the finish-rolled sheet is as follows: the tensile strength is more than or equal to 440MPa, the yield strength is more than or equal to 305MPa, and the elongation is more than or equal to 33 percent; the qualified range of the hardness value is 75HRB to 90 HRB; and putting the annealed coils with qualified mechanical properties and hardness on a small slitting machine.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110827900.3A CN113637831A (en) | 2021-07-22 | 2021-07-22 | Processing technology of SAPH440 high-strength structural steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110827900.3A CN113637831A (en) | 2021-07-22 | 2021-07-22 | Processing technology of SAPH440 high-strength structural steel |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113637831A true CN113637831A (en) | 2021-11-12 |
Family
ID=78417988
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110827900.3A Pending CN113637831A (en) | 2021-07-22 | 2021-07-22 | Processing technology of SAPH440 high-strength structural steel |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113637831A (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106086350A (en) * | 2016-08-29 | 2016-11-09 | 湖北大帆金属制品有限公司 | A kind of processing technique of strip steel |
| CN106834924A (en) * | 2016-12-30 | 2017-06-13 | 日照宝华新材料有限公司 | The method that Thin Specs SAPH440 steel is produced based on ESP bar strip continuous casting and rolling flow paths |
| CN107723427A (en) * | 2017-11-22 | 2018-02-23 | 福清市辉华不锈钢制品有限公司 | A kind of production technology of stainless steel belt |
| CN109957726A (en) * | 2019-03-29 | 2019-07-02 | 江苏省沙钢钢铁研究院有限公司 | Low-cost high-strength cold-rolled annealed plate and manufacturing method thereof |
| CN110904319A (en) * | 2019-12-23 | 2020-03-24 | 新余钢铁股份有限公司 | Manufacturing process of high-carbon tool steel SK85 cold-rolled wide steel strip |
-
2021
- 2021-07-22 CN CN202110827900.3A patent/CN113637831A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106086350A (en) * | 2016-08-29 | 2016-11-09 | 湖北大帆金属制品有限公司 | A kind of processing technique of strip steel |
| CN108165709A (en) * | 2016-08-29 | 2018-06-15 | 武汉佰起科技有限公司 | A kind of strip processing technology for spring leaf |
| CN108220548A (en) * | 2016-08-29 | 2018-06-29 | 武汉佰起科技有限公司 | A kind of processing technology of high-strength steel strip |
| CN108251610A (en) * | 2016-08-29 | 2018-07-06 | 武汉佰起科技有限公司 | A kind of hot rolling technique of strip |
| CN106834924A (en) * | 2016-12-30 | 2017-06-13 | 日照宝华新材料有限公司 | The method that Thin Specs SAPH440 steel is produced based on ESP bar strip continuous casting and rolling flow paths |
| CN107723427A (en) * | 2017-11-22 | 2018-02-23 | 福清市辉华不锈钢制品有限公司 | A kind of production technology of stainless steel belt |
| CN109957726A (en) * | 2019-03-29 | 2019-07-02 | 江苏省沙钢钢铁研究院有限公司 | Low-cost high-strength cold-rolled annealed plate and manufacturing method thereof |
| CN110904319A (en) * | 2019-12-23 | 2020-03-24 | 新余钢铁股份有限公司 | Manufacturing process of high-carbon tool steel SK85 cold-rolled wide steel strip |
Non-Patent Citations (1)
| Title |
|---|
| 王顺兴主编, 哈尔滨：哈尔滨工业大学出版社 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN108251610B (en) | Hot rolling processing technology of strip steel | |
| CN107641759B (en) | Method for producing thin-specification hot forming steel based on CSP (cast Steel plate) process | |
| CN103014452B (en) | 5182 aluminum alloy tab stock substrate and production method thereof | |
| CN109628846B (en) | 1300 MPa-grade ultrahigh-strength cold-rolled steel plate for automobiles and production method thereof | |
| CN102653839B (en) | Low-temperature continuous-annealing interstitial-free atom cold-rolled steel plate and production method thereof | |
| CN103014445B (en) | 5052 aluminum alloy end stock substrate and production method thereof | |
| CN108728751B (en) | IF isotropic steel for improving stamping forming and manufacturing method thereof | |
| US20110168303A1 (en) | High tensile strength steel for container and producing method of the same | |
| CN102416404A (en) | Method for producing cold-rolled steel strips | |
| EP0120976B1 (en) | Process for manufacturing cold-rolled steel for deep drawing | |
| CN105689392A (en) | Production method for ultra-thin cold-rolled enamelled steel strips | |
| WO2010113333A1 (en) | Steel sheet for high‑strength container and manufacturing method thereof | |
| CN102794301A (en) | Manufacture method of cold-rolled electrolytic tin substrate | |
| CN111424150A (en) | SPHC hot-rolled pickled plate without transverse crease defect and production method thereof | |
| CN114433648B (en) | Cold drawing processing method of high-carbon chromium bearing steel guide rail blank | |
| CN113621773A (en) | SK85 carbon tool steel | |
| CN113637831A (en) | Processing technology of SAPH440 high-strength structural steel | |
| CN112501513B (en) | Low-carbon acid-pickled steel with excellent formability and surface quality and production method thereof | |
| CN113981324A (en) | Hot-rolled pickled steel plate with thin specification of less than 3.0mm and high-temperature oxidation resistance for hot forming and production method thereof | |
| CN113913671A (en) | High-temperature oxidation resistant cold-rolled steel plate for hot forming and production and manufacturing method thereof | |
| CN115945917A (en) | Machining process of structural steel for automobile | |
| CN113564474A (en) | Steel plate with yield strength not less than 550MPa and low yield ratio for large-scale petroleum storage tank and production method thereof | |
| CN111636031A (en) | Ultra-low carbon bake-hardening steel and production method thereof | |
| CN115786668A (en) | Processing technology of medium-carbon high-alloy tool steel | |
| CN110883092A (en) | Method for controlling thickness fluctuation of silicon steel |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20211112 |
|
| RJ01 | Rejection of invention patent application after publication |