The welding method of 10CrMo9-10 steel
Technical field
The present invention relates to a kind of welding method, particularly a kind of welding method that is applied to the 10CrMo9-10 steel.
Background technology
Along with the fast development of thermo-power station industry, chemical industry, the container, the pipeline demand that are applied to higher temperature (350 ℃~600 ℃) are also increasing.Material such as the steel such as Q345B, L360MB that traditional pipeline uses, because it does not have enough heat resistances (creep rupture strength or creep strength) and enough hole oxidisability and corrosion resistances, higher engineering or the position of the serviceability temperature such as not competent thermo-power station.And when using the refractory steel welding to produce, the refractory steel of many alloyings has larger cold cracking inclination.For avoiding cold cracking, the multiplex SMAW of traditional welding, gas shielded arc welding, monofilament submerged-arc welding.These welding manner production efficiencys are low.Like this, for the increasing refractory steel of demand, large-duty multi-wire submerged-arc welding technology has broad application prospects.
EN 10028-2 10CrMo9-10 is the steel grade of European standard, and it has improved creep resistance and creep rupture strength by adding the elements such as Mo, Mn, Cr to realize solution strengthening, has improved simultaneously non-oxidizability; By adding the elements such as V, Ti, Nb, stablize tiny carbide when forming high temperature, be distributed on the slide surface of crystal grain, hinder dislocation motion, realize High-Temperature Strengthening; By reducing element S in harmful half a lifetime, the P in steel, realize purifying crystal boundary, improve grain-boundary strength; By normalized treatment, uniform crystal particles is distributed, moderate grain size, the grain boundary area when reducing high temperature.Its chemical composition and mechanical performance are as follows:
0.2% yield strength minimum under high temperature
This kind steel have added more Mo, Cr element, and the hardenability of the steel that significantly improves has reduced the critical cooling rate of steel, and cold cracking inclination is large, easily produce cold crack during welding; S in steel, P content are controlled very lowly, and it is little that fire check produces tendency.In prior art, the welding point of steel grade and mother metal etc. epistasis (creep rupture strength that substantially equates and creep limit), physics uniformity (with the essentially identical physical property of mother metal) and heat endurance (with the essentially identical anti-hydrogen of mother metal and non-oxidizability), anti-brittle failure (doing the water pressure test of 1.5 times of operating pressures under normal temperature) sometimes be difficult to guarantee, the technical staff must guarantee welding quality, avoid producing cold crack, also will keep higher productivity ratio simultaneously.Those skilled in the art is devoted to provide a kind of welding method, welding point is possessed and the essentially identical creep rupture strength of mother metal and creep limit, physical property, anti-hydrogen and non-oxidizability, anti-brittle failure, can effectively prevent again cold cracking simultaneously and possess higher production efficiency.
Summary of the invention
The technical problem to be solved in the present invention is to be difficult to close deficiency for the creep rupture strength that overcomes 10CrMo9-10 shaped steel Seam and heat effected zone after welding in prior art and creep limit, physical property, anti-hydrogen and non-oxidizability, anti-brittle failure and mother metal, a kind of welding method of 10CrMo9-10 shaped steel is provided, assists the workmen to complete in high quality weld job.
The present invention solves above-mentioned technical problem by following technical proposals:
A kind of welding method of 10CrMo9-10 steel, its characteristics be, described method comprises,
Step S
1: bevel for welding is processed as the X-type groove, will treats that with edge milling machines weldment carries out Milling Process, bevel angle is 70 °, to clearing up in described groove and internal and external walls both sides 25mm scope, until expose metallic luster;
Step S
2: treat with the mixed gas arc welding mode welding that weldment positions layer;
Step S
3: treat with the mixed gas arc welding mode welding that weldment carries out prime coat;
Step S
4: treat with the mode of double wire hidden arc welding the welding that weldment carries out packed layer and capping layer;
Step S
5: weldment is carried out the tempering stress-removal process, temperature is 680~730 ℃, can eliminate welding residual stress like this, reduces the hardness of weld seam and heat affected area, improve simultaneously the welding point tissue, improve the stability of comprehensive mechanical property, the high-temerature creep limit and tissue.
Preferably, at step S
1In, confirm groove unfitness of butt joint≤1.5mm, zero defect in welding position and edge 25mm scope thereof.
Preferably, at step S
1In, the root face height for the treatment of weldment is 3mm, the vertical height of outer groove is to treat 1/2nd of weldment gross thickness.
Preferably, at step S
2In, use Ar, CO
2Mist is protected the weldering welding.
Preferably, at step S
2In, welding material is identical during with formal welding, the electric current large 20~40A of welding current during than normal welding, and fusion length is greater than 55mm, weld width, even thickness.
Preferably, at step S
2In, carry out preheating before weldering, preheat temperature is 200~240 ℃, the preheating width be the weldment wall thickness more than 4.5 times and be not less than 150mm.
Preferably, at step S
3In, use Ar, CO
2Mist is protected the weldering welding, carries out preheating before weldering, and preheat temperature is 200~240 ℃, and the preheating width is greater than 150mm.
Preferably, at step S
3In, welding wire is selected ISO17634-A CrMo2Mn model welding wire, and diameter 1.2mm, ratio of gas mixture are Ar:CO
2=82%:18%, gas flow are 17~22L/min, and Ar purity is more than 99.95%; Welding arc voltage is 24~28V, and welding current is 220~260A, and speed of welding is 24~28cm/min, and the backing welding layer thickness is controlled in 3.5~5mm scope.
Preferably, at step S
4In, carry out preheating before weldering, preheat temperature is 200~240 ℃, the preheating width be the weldment wall thickness more than 4.5 times and be not less than 150mm; Interlayer temperature is controlled to be 180~280 ℃;
Preferably, at step S
4In, adopting mariages Lincoln weld welding, it is dc source that front wire bond connects power supply, the reversal connection form, rear silk is AC power; Welding wire is selected ISO17634-A CrMo2Mn model welding wire, and diameter is 3.2mm, coordinates the SJ101 solder flux, and the welding cladding thickness is 25~35mm; Welding arc voltage: front silk 29~31V, rear silk 36~38V; Welding current: front silk 600~650A, rear silk 550~600A; Speed of welding is 120cm/min; Every layer is filled metal thickness is 5.0~6.0mm.
Preferably, ignition tip to the welding wire length between pad is: mixed gas arc welding is 14~19mm, and submerged-arc welding is 22~26mm; Welding wire stretches out rear front silk center and the rear silk line of centres and groove parallel longitudinal, and spot pitch is 18~22mm.
Preferably, pre-thermal recovery electric heating sheets mode heats.
In the present invention, but above-mentioned optimum condition any combination on the basis that meets this area general knowledge namely gets each preferred embodiment of the present invention.
Positive progressive effect of the present invention is: welding point possesses and the essentially identical creep rupture strength of mother metal and creep limit, physical property, anti-hydrogen and non-oxidizability, anti-brittle failure, can effectively prevent again simultaneously cold cracking and possess higher production efficiency, greatly having improved this steel welding procedure.
Description of drawings
Fig. 1 is two position views for the treatment of that the weldment horizontal is to be welded under a specific embodiment of the present invention.
The specific embodiment
Embodiments of the invention describe with reference to the accompanying drawings.In Figure of description, element or device with similar structures or function will represent with identical component symbol.Accompanying drawing is each embodiment of the present invention for convenience of explanation just, is not to carry out to the present invention the explanation of exhaustive, neither limit scope of the present invention.
Two of showing under a specific embodiment of the present invention of Fig. 1 treat the weldment exemplary locations.Below with reference to accompanying drawing, introduce welding method of the present invention, it comprises the following steps:
Step 110, the technical staff treats the weldment horizontal positioned with two 10CrMo9-10 steel, bevel for welding is processed as the X-type groove, to treat that with edge milling machines weldment carries out Milling Process, bevel angle is 70 ° (monolateral 35 °), to clearing up in described groove and internal and external walls both sides 25mm scope, until expose metallic luster.In a preferred embodiment, the root face height for the treatment of weldment is 3mm, and the vertical height of outer groove is 1/2nd of steel plate general thickness.Before welding, confirm groove unfitness of butt joint≤1.5mm, zero defect in welding position and edge 25mm scope thereof.Those skilled in the art will appreciate that the concrete weld size for the treatment of weldment can do along with actual condition suitable adjustment.
Step 120 is used Ar, CO
2Mist positions the welding of weldering in protection weldering mode.Welding material is identical during with formal welding, the electric current large 20~40A of welding current during than normal welding, and fusion length is greater than 55mm, weld width, even thickness.Carry out preheating before weldering, pre-thermal recovery electric heating sheets mode heats, and preheat temperature is 200~240 ℃, the preheating width be the weldment wall thickness more than 4.5 times and be not less than 150mm.The source of welding current of tack welding can be epoch NBC-500.Those skilled in the art will appreciate that mixed gas arc welding also can use other suitable gas to weld.
Step 130 is used Ar, CO
2Mist carries out the welding of prime coat 10 in protection weldering mode.Carry out preheating before protecting the weldering welding, pre-thermal recovery electric heating sheets mode heats, and preheat temperature is 200~240 ℃, and the preheating width is greater than 150mm.In a preferred embodiment, welding wire is selected ISO17634-ACrMo2Mn model welding wire, and diameter 1.2mm, ratio of gas mixture are Ar:CO
2=82%:18%, gas flow are 17~22L/min, and Ar purity is more than 99.95%; Welding arc voltage is 24~28V, and welding current is 220~260A, and speed of welding is 24~28cm/min, and the backing welding layer thickness is controlled in 3.5~5mm scope.
Step 140 treats with the mode of double wire hidden arc welding the welding that weldment carries out packed layer 20 and capping layer 30.Carry out preheating before weldering, preheat temperature is 200~240 ℃, the preheating width be the weldment wall thickness more than 4.5 times and be not less than 150mm; Interlayer temperature is controlled to be 180~280 ℃; In a preferred embodiment, it is dc source that front wire bond connects power supply, the reversal connection form, and rear silk is AC power; Welding wire is selected ISO17634-A CrMo2Mn model welding wire, and diameter is 3.2mm, coordinates the SJ101 solder flux, and the welding cladding thickness is 25~35mm; Welding arc voltage: front silk 29~31V, rear silk 36~38V; Welding current: front silk 600~650A, rear silk 550~600A; Speed of welding is 120cm/min; Every layer is filled metal thickness is 5.0~6.0mm.The source of welding current of front silk can be Lincoln DC-1500 model, and the source of welding current of rear silk can be Lincoln AC-1200 model.
The weldment postwelding carries out tempering, and 680~730 ℃ of temperature can be eliminated welding residual stress, reduces the hardness of weld seam and heat affected area, improves simultaneously the welding point tissue, improves the stability of comprehensive mechanical property, the high-temerature creep limit and tissue.
Those skilled in the art will appreciate that concrete preheating method do not limit, as long as it is all applicable to reach preheating requirement.In a preferred embodiment, ignition tip to the welding wire length between pad is: mixed gas arc welding is 14~19mm, and submerged-arc welding is 22~26mm; Welding wire stretches out rear front silk center and the rear silk line of centres and groove parallel longitudinal, and spot pitch is 18~22mm.
The present invention adopts moderate heat input and multi-pass welding, sets gas flow and speed of welding; Adopt speed of welding faster, reduce the high-temperature residence time of heat affected area, avoid the overheated zone of steel high temperature austenite excessive, crystal grain-growth is too thick, well controls the performance of weld seam and heat affected area, carries out temper by postwelding, can eliminate welding residual stress, reduce the hardness of weld seam and heat affected area, improve simultaneously the welding point tissue, improve the stability of comprehensive mechanical property, the high-temerature creep limit and tissue.Make strong, close physical property, heat endurance, the anti-brittle failure such as basic of itself and mother metal.Wherein welding the number of plies changes with the variation of mother metal thickness.
Those skilled in the art will appreciate that the technical program can not only use in the submerged arc welding operation of 10CrMo9-10 steel, go for equally the weld job of other special steel grade.
Although more than described the specific embodiment of the present invention, it will be understood by those of skill in the art that these only illustrate, protection scope of the present invention is limited by appended claims.Those skilled in the art can make various changes or modifications to these embodiments under the prerequisite that does not deviate from principle of the present invention and essence, but these changes and modification all fall into protection scope of the present invention.