CN1044139C - High strength, high weldability steel bars and wires for prestressed concrete - Google Patents
High strength, high weldability steel bars and wires for prestressed concrete Download PDFInfo
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- CN1044139C CN1044139C CN 95107083 CN95107083A CN1044139C CN 1044139 C CN1044139 C CN 1044139C CN 95107083 CN95107083 CN 95107083 CN 95107083 A CN95107083 A CN 95107083A CN 1044139 C CN1044139 C CN 1044139C
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- 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
- C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
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Abstract
A high strength steel bar or wire having better weld-ability for prestressed concrete is improved in the relaxation at high temperature thus increasing the toughness. It contains 0.3 % to 2.0 % of silicon, 0.08 % to 0.35 % of molybdenum and predetermined amounts of carbon and manganese. If desired, it may contain titanium and boron. In particular, the silicon and the molybdenum are not less 1 % in the Si+4Mo combination. At heat treatment, the steel bar or wire is rapidly heated within 20 seconds so that a fine austenite microstructure of the grain size number 9.0 or more is formed. More preferably, while the steel bar or wire is heated to a tempering temperature, it is loaded with a bending strain of not more than 3 % before cooled down rapidly.
Description
The present invention relates to be used for the reinforcing bar and the steel wire of prestressed concrete, they have improved mechanical property, and intensity, weldability improve, and high humidity is loose to be reduced.
General reinforcing bar and the steel wire (hereafter PC reinforcing bar) that all requires to be used for prestressed concrete has high tensile strength to guarantee effective prestress.According to the requirement of JIS, high-quality PC reinforcing bar should have up to 1420N/mm
2Tensile strength.Usually, in order to make concrete pile and concrete column efficiently, the raw concrete that is embedded with the PC reinforcing bar is heated above 100 ℃ by steam high-pressure curing technology, to improve its mechanical strength.But Heating temperature is high more, reduces the loose all the more speed of PC reinforcing bar to concrete prestress effect.Therefore, require the stress relaxation of PC reinforcing bar under hot conditions as far as possible little.In addition, require the PC reinforcing bar to have high uniform unit elongation, this is for fundamental factor of given flexible.
In some applications, weldability also is necessary to the PC reinforcing bar.For example, with the binding of the PC reinforcing bar of many parallel placements together, and spot weld and form steel framed structure on the spiral wire, this structure is used for the enhancing of concrete pile or concrete column.This weldability should be enough high, so that the spot-welding technology of available routine is welded in reinforcing bar on the spiral wire.
As everyone knows, the PC reinforcing bar is made by proper heat treatment (comprise quench and tempering), to give performance that its needs or more particularly, has the good unification of intensity and flexible.When thermal treatment, the raw material reinforcing bar or the steel wire of hot rolling are cold drawing to certain-length, and surperficial embossing makes it be easy to combine with concrete, and again through quenching and temper, usually, when reinforcing bar or steel wire transported continuously, they were quenched and tempering as requested.
In order to reduce the silicone content of conventional PC reinforcing bar to be brought up to 0.5～2.0% by 0.2～0.3% (weight below is weight ratio), or reach as high as 2.3% being higher than relaxing under 100 ℃ of temperature, this opens the spy has among the clear 62-49334 (1987) openly.In addition, this openly attempted before cooling off fast, reached the lax effect of not losing uniform elongation of reduction high temperature by the PC reinforcing bar being heated to a tempering temperature and applying minimum strain simultaneously.
But it is big that the resistance of this high silicon PC reinforcing bar becomes, and causes the welding strength of spot welding to reduce (unless weldingvoltage increases 50%).Because use various PC reinforcing bars to make steelframe at the scene, need regulating voltage continually, so welding process take a long time with Different Silicon content.For this reason, applicant of the present invention has developed and has introduced improved welding property by using molybdenum, and this opens among flat 3-151445 and the 3-285045 (1991) the spy narration.Should understand, molybdenum only could obtain with high price on market.Therefore, an object of the present invention is to provide the less high-strength PC reinforcing bar of a kind of molybdenum content, this reinforcing bar weldability strengthens, and mechanical property is improved.
The purpose of this invention is to provide a kind of high-strength PC reinforcing bar, its tensile strength is up to 1420N/mm
2, the high temperature relexation reduces, and toughness improves, and does not lose welding property.More particularly, the reinforcing bar high-strength, high weldability that is used for prestressed concrete according to the present invention is characterised in that, it contains 0.15%～0.40% carbon, 0.3～2.0% silicon, 0.4%～1.6% manganese and 0.08～0.35% molybdenum (all by weight), be no less than 1.0% (weight) with Si+4Mo bonded silicon and molybdenum, surplus is iron and inevitable impurity, and this reinforcing bar has autstenitic grain size more than or equal to 9.0 thin microstructure.Preferably, this PC reinforcing bar also contains 0.01～0.05% titanium and 0.0005%～0.005% boron, all by weight.
A kind of method of producing according to above-mentioned PC reinforcing bar of the present invention, comprise: with the raw material reinforcing bar 20 seconds internal heating to 850 ℃～1050 ℃, this raw material reinforcing bar contains 0.15%～0.40% carbon, 0.3～2.0% silicon, 0.4%～1.6% manganese and 0.08～0.35% molybdenum (all by weight), be no less than 1.0% (weight) with Si+4Mo bonded silicon and molybdenum, surplus is iron and inevitable impurity, with its rapid quenching; In 25 seconds, be heated a tempering temperature, and cooling fast, so that the formation austenite crystal number of degrees are more than or equal to 9.0 thin microstructure.Preferably, after being heated to tempering temperature, can apply the load that is no more than 3% flexural strain, then cooling apace to the PC reinforcing bar.
Fig. 1 is the content and the lax graph of relation of high temperature of expression silicon and molybdenum.
Fig. 2 is expression silicon and the content of molybdenum and the graph of relation of welding current and welding strength.
Fig. 3 has the austenitic microstructure photo earlier according to PC reinforcing bar of the present invention.
According to the present invention, provide a kind of and contain an amount of molybdenum with the PC reinforcing bar of reduction silicone content to the adverse effect of weldability, and silicone content is that reduction high temperature is lax necessary, so that these reinforcing bars are not improving under the weldingvoltage prerequisite and can weld reliably. Be to obtain optimum efficiency, should carefully determine the molybdenum/silicon ratio in the content, because the effect (it causes Carbide Precipitation) of the molybdenum formation austenite crystal number of degrees 9.0 or higher thin microscopic structure. As a result, although PC reinforcing bar of the present invention contains the molybdenum of minimum costliness, on intensity and toughness, increase is arranged.
The present inventor is by a series of experiment, carries out and checked in the PC reinforcing bar that makes with conventional cold-drawn, quenching and tempering process and added essential element. Fig. 1 has represented that some have the lax result of the high temperature of the PC reinforcing bar of Different Silicon content and molybdenum content (they contain or not titaniferous and boron) under 180 ℃, wherein to represent respectively molybdenum content be 0,0.1%, 0.2% and 0.3% PC reinforcing bar for A, B, C and D, and blank and solid symbol represents respectively to contain or the situation of titaniferous and boron not. Obviously can find out that although having of silicon is beneficial to that to reduce high temperature lax, its effect is tending towards saturated when surpassing 1.5%. It can also be seen that molybdenum is favourable to reducing high temperature lax. But the existence of titanium and boron relaxes to control high temperature does not almost have effect.
The present inventor has carried out the test of welding strength of spot welding place of a check PC reinforcing bar and spiral wire.More particularly, the test PC reinforcing bar of each diameter 9.2mm is being welded on the spiral wire of diameter 3.2mm under the 1.45V weldingvoltage with conventional electric spot welding technology, the specific conductivity between reinforcing bar and the steel wire is measured by electric current.Then, utilize the shear strength test of " the Welded steel net " requirement that meets JIS G 3551 to carry out the mechanical strength detection of solder joint.
The results are shown in Fig. 2, when the PC reinforcing bar does not contain molybdenum and silicone content less than 1% the time, the specific conductivity of its solder joint reduces, so physical strength reduces.When silicone content is higher than 1.5%, the specific conductivity and the intensity that contain molybdenum PC reinforcing bar will not change or reduce less.In addition, in this case, the existence of titanium and boron has some effect.
From above-mentioned experimental result, the present invention is the PC reinforcing bar for need directly obtaining.To introduce the chemical constitution of PC reinforcing bar below.
Preferably, the PC reinforcing bar contains the carbon of 0.15-0.40%, because if carbon content is lower than 0.15%, then its intensity will be low to moderate disadvantageous level.If carbon content is higher than 0.40%, its toughness and welding property all will descend.
Silicone content is 0.3-2.0%.If be lower than 0.3%, even be added with molybdenum, it is lax also to be difficult to reduce its high temperature.If silicone content is higher than 2.0%, high temperature is lax with saturated, but toughness and welding property reduce.
This PC reinforcing bar contains the manganese of 0.4-1.6%.The existence of manganese is carried out hardening process easily, and uniform elongation and flexible raising are had effect.If its content is lower than 0.4%, this advantage will lose.If its content is higher than 1.6%, after quenching, will there be the austenite of can not ignore, therefore can reduce its mechanical strength.Thus, 0.4～1.6% scope is best.
Molybdenum content is 0.08～0.35%, and molybdenum and the silicon high temperature that can suppress the PC reinforcing bar that combines is lax, even silicone content increases, it also can keep welding property, and in addition, it has also improved hardening effect, and help the formation of close grain microstructure, therefore increased mechanical strength and toughness.If molybdenum content is lower than 0.08%, above-mentioned advantage will reduce, if be higher than 0.35%, then favourable effect is with saturated, and expense then can rise.
In detail, need to keep being not less than 1.0% with Si+4Mo form bonded silicon and molybdenum.For being limited in a set-point with high temperature is lax, Si+4Mo preferably is not less than 1.0%, and more preferably 1.4% or higher.Experiment finds, when the combination of above-mentioned silicon and molybdenum is met and keeps its predetermined value respectively, and the PC reinforcing bar that availability is superior.
In addition, for strengthening welding property, can add titanium and boron.Titanium content be lower than 0.01% o'clock not too effective, when it surpasses 0.05%, will impair improvement.Not too effective when boron content is lower than 0.0005%, and it is constant substantially to surpass 0.005% o'clock its effect.Too much boron can make reinforcing bar crack when hot rolling or rupture.
It is 9.0 or bigger thin austenite crystal that PC reinforcing bar of the present invention has grain size number.Grain size number has definition in JIS G 0551, the number of die n n=2 in every square millimeter
N+3Expression, and grain size number is N.Fig. 3 is the Photomicrograph that shows the austenite phase of PC reinforcing bar of the present invention, and it has grain size number is 10.6 thin microstructure.Can obtain the austenite structure of Fig. 3 by thermal treatment before the quenching of the present invention.By quenching, austenite changes the thinner martensitic phase of crystal grain mutually into, thus the intensity of PC reinforcing bar and toughness than grain size number less than 9.0 conventional reinforcing bar height.
PC reinforcing bar of the present invention is produced like this: raw steel is cold drawing to the diameter of expectation, can makes it be easy to combine with concrete at its surperficial embossing if desired, quench and tempering.During quenching, in 20 seconds, the PC reinforcing bar is warming up to 850-1050 ℃.This rapid heating process has kept the nucleus of many austenite crystals that produced by cold-drawn, thereby to have formed grain size number be 9.0 or bigger thin austenitic microstructure.Can carry out accelerated warming by high-frequency induction heating or direct resistive heating.Surpass 20 seconds if be heated to the used time of austenitizing temperature, the small number of crystal nucleus of generation may have grown into big crystal grain, the therefore thin microstructure that can not obtain to expect when heating up.
Soaking time when quenching temperature should be lacked as much as possible, but wants to form uniform austenite structure.Although raw material of the present invention contains the carbide precipitate of Mo, can suppress growing up of austenite crystal, soaking time was preferably in 20 seconds.Quenching velocity after the insulation should be not less than 100 ℃/second, to form complete martensitic stucture.
Carry out tempering then, in 25 seconds, be warming up to tempering temperature as far as possible to form the martensitic stucture of average tempering.Usually determine in 400-550 ℃ of scope that tempering temperature is to reach predetermined tensile strength, for example 1420N/mm
2After being warming up to tempering temperature, under this temperature, be incubated for some time, for example 10 seconds, more quickly with the reinforcing bar cooling, to prevent owing to organizing chap to cause strength degradation.
As a method that is more preferably of the present invention, in being heated to the tempering temperature process, apply flexural strain less than 3% to reinforcing bar, it is lax that this will reduce high temperature further.Applying of flexural strain can realize that these bending rolls are similar to the roller of straightener by row's multiple bending roll, and the heating unit (for example induction heater) that is arranged in the reinforcing bar that is used for heating continuous confession afterwards.Because the dislocation that forms in the flexural strain material is tangled mutually, and dislocation has been limited motion under the effect of entanglement precipitate such as carbide and nitride etc., it is lax that this has reduced high temperature.
Flexural strain is less than or equal to 3%, more preferably, is less than or equal to 2%.If strain is too high, will reduce toughness and uniform elongation.If after applying flexural strain, reinforcing bar is long in the tempering temperature soaking time, and the dislocation of generation will disappear, and therefore loses its superior performance.Therefore, in the near future, for example just should implement to force cooling in 10 seconds.
Embodiment
To be cold drawing to the reinforcing bar of diameter 9.2mm by the hot-rolled steel that different chemical shown in the table 1 is formed.In 7 seconds, reinforcing bar is heated to 950 ℃ with induction heating, before with water quenching, under this temperature, was incubated for 6 seconds.With one group of reinforcing bar 5 second internal heating to tempering temperature, under this temperature the insulation 10 seconds, use water cooling again.Another group reinforcing bar is heated to same tempering temperature, and pressurization makes the flexural strain of its generation 0.9%, and the pressurization back kept 5 seconds under this temperature, used water cooling again.Another group reinforcing bar is heated in 25 seconds with the front respectively organizes 950 ℃ of identical temperature.Change tempering temperature according to forming, the PC reinforcing bar tensile strength that obtains is greater than 1420N/mm
2
Table 1
| No． | Chemical constitution (%) | |||||||||
| C | Si | Mn | P | S | Mo | Ti | B | Si+4Mo | ||
| The present invention | 1 | 0.31 | 0.51 | 0.90 | 0.011 | 0.010 | 0.27 | 0.02 | 0.0016 | 1.59 |
| 2 | 0.28 | 0.82 | 0.62 | 0.015 | 0.008 | 0.24 | 0.02 | 0.0019 | 1.78 | |
| 3 | 0.32 | 1.01 | 0.82 | 0.009 | 0.008 | 0.20 | 0.02 | 0.0018 | 1.81 | |
| 4 | 0.29 | 1.53 | 0.98 | 0.012 | 0.011 | 0.12 | 0.02 | 0.0018 | 2.01 | |
| 5 | 0.33 | 1.82 | 0.70 | 0.011 | 0.009 | 0.11 | 0.02 | 0.0020 | 2.26 | |
| 6 | 0.30 | 0.35 | 1.20 | 0.016 | 0.010 | 0.31 | 0.02 | 0.0017 | 1.59 | |
| 7 | 0.34 | 0.82 | 1.10 | 0.010 | 0.008 | 0.25 | - | - | 1.82 | |
| 8 | 0.30 | 1.00 | 0.80 | 0.008 | 0.012 | 0.22 | - | - | 1.88 | |
| 9 | 0.29 | 1.72 | 0.85 | 0.009 | 0.009 | 0.18 | - | - | 2.44 | |
| Comparative Examples | 10 | 0.32 | 0.25 | 0.92 | 0.010 | 0.011 | 0.18 | 0.02 | 0.0022 | 0.97 |
| 11 | 0.28 | 0.50 | 0.80 | 0.012 | 0.008 | 0.12 | 0.02 | 0.0020 | 0.98 | |
| 12 | 0.30 | 0.83 | 0.76 | 0.009 | 0.012 | - | 0.02 | 0.0018 | 0.83 | |
| 13 | 0.27 | 1.05 | 0.84 | 0.014 | 0 011 | - | 0.02 | 0.0017 | 1.05 | |
| 14 | 0.31 | 2.03 | 0.82 | 0.010 | 0.009 | - | 0.02 | 0.0021 | 2.03 | |
Carry out a series of experiment and check austenite grain size, mechanical property, stress relaxation and welding strength the results are shown in table 2 and table 3.Obviously, the mechanical property of PC reinforcing bar of the present invention and conventional PC reinforcing bar quite, even higher.Especially, grain size number is more than or equal to the uniform elongation height of 9.0 PC reinforcing bar of the present invention, and other performance is also very superior.
Relaxation test is carried out under two differing tempss, promptly carries out under room temperature and 180 ℃, applies 1020N/mm with detection
2Initial stress (predetermined yielding stress 1275N/mm
280%) time, constant folder apart from the time stress reduction.Lax in order to detect high temperature, with test strip at 4 hours internal heating to 180 ℃, insulation 3 hours under this temperature again, cooling gradually then.Measured later in 23 hours applying initial stress.As can be seen, obtaining best result with Si+4Mo bonded silicon and molybdenum content on greater than 1.0% PC reinforcing bar.It can also be seen that in the material of same amount, applying little flexural strain when tempering, can to reduce high temperature lax.
Table 2
* Y: be N: not
| No． | Condition * | Grain size number | Yielding stress (N/mm 2) | Tensile strength (N/mm 2) | Uniform elongation (%) | Tension set (%) | |||
| Material | Rapid heating | Flexural strain | |||||||
| The present invention | 1A | 1 | Y | Y | 10.1 | 1451 | 1479 | 3.6 | 10.9 |
| 1B | Y | N | 10.1 | 1452 | 1478 | 3.6 | 11.1 | ||
| 2A | 2 | Y | Y | 10.3 | 1442 | 1475 | 3.5 | 10.9 | |
| 3A | 3 | Y | Y | 10.4 | 1439 | 1466 | 3.7 | 10.8 | |
| 3B | Y | N | 10.4 | 1453 | 1474 | 3.5 | 10.6 | ||
| 4A | 4 | Y | Y | 10.6 | 1452 | 1476 | 3.8 | 10.8 | |
| 5A | 5 | Y | Y | 10.7 | 1449 | 1463 | 3.5 | 10.8 | |
| 5B | Y | N | 10.7 | 1452 | 1482 | 3.6 | 11.0 | ||
| 6A | 6 | Y | Y | 10.2 | 1440 | 1473 | 3.7 | 11.2 | |
| 7A | 7 | Y | Y | 10.5 | 1445 | 1479 | 3.5 | 10.7 | |
| 8A | 8 | Y | Y | 10.3 | 1450 | 1481 | 3.6 | 10.7 | |
| 9A | 9 | Y | Y | 10.4 | 1444 | 1478 | 3.5 | 10.8 | |
| Comparative Examples | 1C | 1 | N | Y | 8.6 | 1450 | 1468 | 3.1 | 9.9 |
| 3C | 3 | N | Y | 8.5 | 1453 | 1464 | 2.9 | 10.2 | |
| 5C | 5 | N | Y | 8.7 | 1455 | 1470 | 3.0 | 10.1 | |
| 10A | 10 | Y | Y | 10.4 | 1448 | 1482 | 3.4 | 10.8 | |
| 11A | 11 | Y | Y | 10.4 | 1450 | 1478 | 3.5 | 10.6 | |
| 11B | Y | N | 10.4 | 1439 | 1473 | 3.4 | 10.9 | ||
| 11C | N | Y | 8.6 | 1457 | 1475 | 2.9 | 10.0 | ||
| 12A | 12 | Y | Y | 9.9 | 1445 | 1472 | 3.3 | 10.3 | |
| 13A | 13 | Y | Y | 10.0 | 1447 | 1470 | 3.4 | 10.7 | |
| 14A | 14 | Y | Y | 9.7 | 1445 | 1468 | 3.3 | 10.4 | |
Table 3
| No. | Stress relaxation (%) | Weldability shearing resistance (N) | ||
| Room temperature | High temperature | |||
| The present invention | 1A | 0.34 | 7.3 | 1480 |
| 1B | 0.33 | 12.3 | 1470 | |
| 2A | 0.41 | 7.4 | 1499 | |
| 3A | 0.38 | 6.5 | 1470 | |
| 3B | 0.33 | 11.0 | 1450 | |
| 4A | 0.39 | 6.4 | 1392 | |
| 5A | 0.30 | 6.9 | 1382 | |
| 5B | 0.35 | 11.8 | 1401 | |
| 6A | 0.31 | 8.0 | 1519 | |
| 7A | 0.38 | 7.6 | 1470 | |
| 8A | 0.37 | 6.4 | 1519 | |
| 9A | 0.34 | 7.0 | 1450 | |
| Comparative Examples | 1C | 0.35 | 8.5 | 1441 |
| 3C | 0.36 | 8.1 | 1392 | |
| 5C | 0.36 | 8.2 | 1372 | |
| 10A | 0.41 | 9.5 | 1421 | |
| 11A | 0.39 | 10.1 | 1480 | |
| 11B | 0.40 | 15.5 | 1450 | |
| 11C | 0.38 | 13.0 | 1362 | |
| 12A | 0.33 | 10.3 | 1352 | |
| 13A | 0.35 | 9.4 | 1127 | |
| 14A | 0.34 | 7.7 | 862 | |
Carry out the welding strength test with same way as noted earlier.Obviously, the PC reinforcing bar that silicon content is higher, molybdenum is having more superiority aspect the enhancing tensile strength.Can be clear that also the existence of titanium and boron has reduced the discordance of intensity, therefore improve mechanical property.
As mentioned above, PC reinforcing bar of the present invention is effective on reduction high temperature is lax.And high temperature relaxes and obviously can aggravate in producing the used steam high-pressure curing of prestressed concrete in batches.They are not using under the special welding conditions, are favourable to forming the sufficiently high enhancing steelframe of welding strength by spot welding.In addition, the PC reinforcing bar satisfies in intensity under the peak demand prerequisite of relevant criterion, and its toughness is also very high, thereby mechanical property preferably is provided.
Claims (5)
1. a reinforcing bar or steel wire that is used for high-strength, the high weldability of prestressed concrete, it contains 0.15%～0.40% carbon, 0.3～2.0% silicon, 0.4%～1.6% manganese and 0.08～0.35% molybdenum (all by weight), wherein be no less than 1.0% (weight) with Si+4Mo bonded silicon and molybdenum, surplus is iron and inevitable impurity, and this reinforcing bar has the austenite crystal number of degrees more than or equal to 9.0 thin microstructure.
2. according to the steel wire or the reinforcing bar of high-strength, the high welding performance that is used for prestressed concrete of claim 1, also contain 0.01%～0.05% titanium and 0.0005%～0.005% boron (all by weight).
3. a production is used for high-strength, the reinforcing bar of high weldability of prestressed concrete or the method for steel wire, may further comprise the steps:
With the raw material reinforcing bar 20 seconds internal heating to 850 ℃～1050 ℃, this raw material reinforcing bar contains 0.15%～0.40% carbon, 0.3～2.0% silicon, 0.4%～1.6% manganese and 0.08～0.35% molybdenum (all by weight), wherein be no less than 1.0% (weight) with Si+4Mo bonded silicon and molybdenum, surplus is iron and inevitable impurity, with its rapid quenching; In 25 seconds, be heated 400-550 ℃ of tempering temperature, and cooling fast, so that the formation austenite crystal number of degrees are more than or equal to 9.0 thin microstructure.
4. be used for high-strength, the reinforcing bar of high weldability of prestressed concrete or the method for steel wire according to the preparation of claim 3, wherein reinforcing bar or steel wire also contain 0.01%～0.05% titanium and 0.0005%～0.005% boron (all by weight).
5. according to the method for claim 3 or 4, wherein after being heated to tempering temperature, apply load, make its flexural strain be no more than 3%, then cooling fast to steel wire or reinforcing bar.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6165783A JP2864348B2 (en) | 1994-06-27 | 1994-06-27 | High strength and high weldability steel rod or steel wire for prestressed concrete and method for producing the same |
| JP165783/94 | 1994-06-27 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1121535A CN1121535A (en) | 1996-05-01 |
| CN1044139C true CN1044139C (en) | 1999-07-14 |
Family
ID=15818932
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 95107083 Expired - Lifetime CN1044139C (en) | 1994-06-27 | 1995-06-26 | High strength, high weldability steel bars and wires for prestressed concrete |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JP2864348B2 (en) |
| CN (1) | CN1044139C (en) |
| GB (1) | GB2290800B (en) |
| HK (1) | HK1001348A1 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1078626C (en) * | 1999-04-09 | 2002-01-30 | 清华大学 | High-silicon abrasion resistant cast steel |
| KR100536660B1 (en) * | 2003-12-18 | 2005-12-14 | 삼화강봉주식회사 | Steel wire with superior impact absorption energy at law temperature and the method of making the same |
| CN102061370A (en) * | 2011-01-31 | 2011-05-18 | 中国钢研科技集团有限公司 | Production process of rebar for concrete |
| CN103643135B (en) * | 2013-11-20 | 2015-12-30 | 上海交通大学 | Tensile strength 2000Mpa and above PC rod iron and heat treating method |
| CN103643125B (en) * | 2013-11-21 | 2015-10-28 | 江苏天舜金属材料集团有限公司 | A kind of steel bar for prestressed concrete and production technique thereof |
| JP2017179399A (en) * | 2016-03-28 | 2017-10-05 | 高周波熱錬株式会社 | Steel material for building |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT271532B (en) * | 1964-02-20 | 1969-06-10 | Krupp Ag Huettenwerke | Steel for components that are subject to long-term tensile stress, especially prestressed concrete steel |
| NL170159C (en) * | 1973-06-04 | 1982-10-01 | Estel Hoogovens Bv | METHOD FOR MANUFACTURING WELDABLE LOW CARBON STEEL MATERIAL BY CONTROLLED COOLING |
| DE2967517D1 (en) * | 1979-06-08 | 1985-10-31 | Henrik Giflo | Reinforcement steel with high mechanical strength |
-
1994
- 1994-06-27 JP JP6165783A patent/JP2864348B2/en not_active Expired - Lifetime
-
1995
- 1995-05-26 GB GB9510785A patent/GB2290800B/en not_active Expired - Fee Related
- 1995-06-26 CN CN 95107083 patent/CN1044139C/en not_active Expired - Lifetime
-
1998
- 1998-01-16 HK HK98100397A patent/HK1001348A1/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| GB2290800A (en) | 1996-01-10 |
| JPH0813082A (en) | 1996-01-16 |
| JP2864348B2 (en) | 1999-03-03 |
| CN1121535A (en) | 1996-05-01 |
| HK1001348A1 (en) | 1998-06-12 |
| GB9510785D0 (en) | 1995-07-19 |
| GB2290800B (en) | 1997-07-23 |
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