High ductility cold rolled reinforcing steel bar with ribs production technique
Technical field
The present invention relates to a kind of production technique of metallic substance, specifically is a kind of high ductility cold rolled reinforcing steel bar with ribs production technique.
Background technology
Cold rolled reinforcing steel bar with ribs is to develop novel building rolling shapes rapidly the twentieth century later stage both at home and abroad, cold rolled reinforcing steel bar with ribs be with hot rolling dish circle through the cold rolling tube reducing of multiple tracks, press together rib and after eliminating internal stress, form a kind ofly have two or three meniscate reinforcing bars.Because cold rolled reinforcing steel bar with ribs has intensity height, good, the easy processing of plasticity and strong with the cement bond stress, can save characteristics such as steel in a large number, cold rolled reinforcing steel bar with ribs is in prestressed concrete member, it is the renewal product of cold-drawn low-carbon wire, in cast-in-place concrete structure, then replaceable I grade reinforcing steel to save steel, is a kind of preferably in the similar cold working steel.
The cold rolled reinforcing steel bar with ribs that adopts the traditional cold roll process to produce, metallographic structure is thick, inhomogeneous, contain martensite, austenite, ferrite and perlite in the metallographic structure, the cold rolled reinforcing steel bar with ribs that adopts common I grade reinforcing steel (Q215 coils circle) to produce, according to the GB13788-2008 standard, the mechanical property of cold rolled reinforcing steel bar with ribs CRB550 is: R
P0.2〉=500MPa, R
m〉=550MPa, A
Gt〉=2.0%.In order to improve the performance of reinforcing bar, need to add trace elements such as titanium, niobium and vanadium in III, the IV grade high-strength reinforcing bar, this has just increased the tooling cost of reinforcing bar.Along with the development of construction industry, also more and more higher to the requirement of construction(al)steel.Because the intensity and the extension property of I, II grade reinforcing steel are on the low side, country takes measures to apply III, IV grade high-strength reinforcing bar at present, eliminates I, II grade reinforcing steel.
Summary of the invention
The object of the present invention is to provide a kind of high ductility cold rolled reinforcing steel bar with ribs production technique, through after this art breading, the interior tissue and the grain fineness number of reinforcing bar change, thereby the intensity of reinforcing bar and unit elongation all are improved with normal carbon steel disk circle.
The present invention takes following technical scheme to realize:
A kind of high ductility cold rolled reinforcing steel bar with ribs production technique, described production technique comprises following step:
(1) will coil circle through one milling train tube reducing, tube reducing is than being 0.79-0.87;
(2) with the reinforcing bar after one milling train tube reducing in the step (1) again through two road milling train tube reducings indentations simultaneously, tube reducing is than being 0.59-0.88;
(3) with the reinforcing bar thermal treatment 1-3s under 550-670 ℃ temperature after two road milling train tube reducings while indentations in the step (2);
(4) with the reinforcing bar naturally cooling in air after the thermal treatment in the step (3).
Above-mentioned tube reducing ratio is meant that the round original section of sectional area/dish after the processing amasss.
The described dish circle trade mark is Q235.
Described high ductility cold rolled reinforcing steel bar with ribs specification is φ 5-φ 14mm.This high ductility cold rolled reinforcing steel bar with ribs is mainly used in the civil construction field, as capital constructions such as house, highway, railway, bridge, power station, harbour, hydro project, mine and equipment installations.
Utilize the reinforcing bar after the processes of the present invention, with the plain steel disk circle of ordinary steel is raw material, interior tissue, the grain fineness number of reinforcing bar change, thereby the intensity of reinforcing bar and unit elongation all are improved, check with reference to GB1499.2-2007 and GB/T13298-1991 according to national structural steel quality supervision and test center, metallographic structure is even, and metallographic structure is ferrite and perlite, and its mechanical property is: R
P0.2〉=525MPa, R
m〉=600MPa, A
5.85〉=20%, A
Gt〉=5%.Utilize the mechanical property of the reinforcing bar after the processes of the present invention to be better than the mechanical property (R of III level cold rolled reinforcing steel bar with ribs
E1〉=400MPa, R
m〉=540MPa, A 〉=16%, A
Gt〉=7.5%), improve than the tensile strength of III level steel about 15%, near the performance index of ⅣJi Gang.
The invention has the beneficial effects as follows:
A kind of high ductility cold rolled reinforcing steel bar with ribs production technique of the present invention, produce high ductility cold rolled reinforcing steel bar with ribs through milling train tube reducing, milling train moulding, process of thermal treatment mode, the plain steel disk of ordinary steel is through after this art breading, the interior tissue and the grain fineness number of reinforcing bar change, thereby the intensity of reinforcing bar and unit elongation all are improved, improve than the tensile strength of III level steel about 15%, near the performance index of ⅣJi Gang.Compare with micro-III, IV level hot rolled ribbed steel bars such as having added titanium, niobium and vanadium, reduced the tooling cost of reinforcing bar, and cold rollingly compare energy-saving and environmental protection more with hot rolling.
Embodiment
Below by specific embodiment the present invention is described in further detail.
Embodiment 1
A kind of high ductility cold rolled reinforcing steel bar with ribs production technique can comprise following step:
(1) the Q215 dish is round through one milling train tube reducing, the tube reducing ratio is 0.87;
(2) with the reinforcing bar after one milling train tube reducing in the step (1) again through two road milling train tube reducings indentations simultaneously, the tube reducing ratio is 0.88;
(3) with the reinforcing bar thermal treatment 1s under 550 ℃ temperature after two road milling train tube reducings while indentations in the step (2);
(4), get the high ductility cold rolled reinforcing steel bar with ribs of CRB600H with the reinforcing bar naturally cooling in air after the thermal treatment in the step (3).
Described I grade reinforcing steel is after the above production technique processing, and its specification is φ 5 one φ 14mm.This high ductility cold rolled reinforcing steel bar with ribs is mainly used in the civil construction field, as capital constructions such as house, highway, railway, bridge, power station, harbour, hydro project, mine and equipment installations.
Utilize the reinforcing bar after the processes of the present invention, the internal stress of reinforcing bar is eliminated, tissue, grain fineness number change, thereby the intensity of reinforcing bar and unit elongation all are improved, check with reference to GB1499.2-2007 and GB/T13298-1991 according to national structural steel quality supervision and test center, metallographic structure is even, and metallographic structure is ferrite and perlite, and its mechanical property is: R
P0.2〉=525MPa, R
m〉=600MPa, A
5.85〉=20%, A
Gt〉=5%.Utilize the mechanical property of the reinforcing bar after the processes of the present invention to be better than the mechanical property (R of III level steel
E1〉=400MPa, R
m〉=540MPa, A 〉=16%, A
Gt〉=7.5%), improve than the tensile strength of III level steel about 15%, near the performance index of ⅣJi Gang.
Embodiment 2
A kind of high ductility cold rolled reinforcing steel bar with ribs production technique can comprise following step:
(1) the Q235 dish is round through one milling train tube reducing, the tube reducing ratio is 0.87;
(2) with the reinforcing bar after one milling train tube reducing in the step (1) again through two road milling train tube reducings indentations simultaneously, the tube reducing ratio is 0.59;
(3) with the reinforcing bar thermal treatment 3s under 670 ℃ temperature after two road milling train tube reducings while indentations in the step (2);
(4), get the high ductility cold rolled reinforcing steel bar with ribs of CRB650H with the reinforcing bar naturally cooling in air after the thermal treatment in the step (3).
Utilize the reinforcing bar after the processes of the present invention, interior tissue, the grain fineness number of reinforcing bar change, thereby the intensity of reinforcing bar and unit elongation all are improved, check with reference to GB1499.2-2007 and GB/T13298-1991 according to national structural steel quality supervision and test center, metallographic structure is even, metallographic structure is ferrite and perlite, and its mechanical property is: R
P0.2〉=585MPa, R
m〉=650MPa, A
100〉=7.0%, A
Gt〉=5.0%.
Embodiment 3
A kind of high ductility cold rolled reinforcing steel bar with ribs production technique can comprise following step:
(1) the Q215 dish is round through one milling train tube reducing, the tube reducing ratio is 0.85;
(2) with the reinforcing bar after one milling train tube reducing in the step (1) again through two road milling train tube reducings indentations simultaneously, the tube reducing ratio is 0.63;
(3) with the reinforcing bar thermal treatment 2s under 610 ℃ temperature after two road milling train tube reducings while indentations in the step (2);
(4) with the reinforcing bar naturally cooling in air after the thermal treatment in the step (3).
All the other are with embodiment 1.