The P92 steel welds with ultralow hydrogen basic electrode
Technical field
Belong to the welding technology field in the Materials Processing Engineering, this invention is mainly used in the welding of P92 steel.
Background technology
Since the eighties in 20th century, countries such as U.S., moral, method, day have successively developed a series of novel 9 ~ 12% chromium martensitic refractory steel, and they can be used for steam parameter and reach 600/610 ℃, the overcritical and ultra-supercritical boiler unit of 25MPa.Typical case's steel grade has: contain T/P91, the T/P92 (NF616) of 9%Cr and contain the T/P122 (HCM12A) of 12%Cr.These steel grades are that former T/P9, F12 are improved and the high-performance refractory steel that obtains, and their high-temperature and durable mechanical property obviously is better than low-alloy pearlite heat resisting steel.The appearance of novel martensite heat resisting steel, for the power station unit to big capacity, high parameter direction develop provide may and safety assurance.
The T/P92 steel is the content (0.5%Mo) that suitably reduces molybdenum element on the basis of T/P91 steel, and it is about 1.5% so that the molybdenum equivalent (Mo+0.5W) of material is mentioned from 1% of T/P91 steel to add a certain amount of tungsten (1.8%W) simultaneously, has also added micro-boron.Compare with other chromium-molybdenum heat resisting steel, the high-temperature corrosion resistance of the T/P92 steel after the alloying improvement is similar to the 9%Cr steel with oxidation susceptibility, but the elevated temperature strength of material and croop property have obtained further raising, near austenitic steel TP347H.Major advantage is, under identical operating temperature, pressure or projected life condition, can further reduce the weight of station boiler and pipe-line system; Perhaps under same physical dimension, further improve the structure Design operating temperature, thereby improve the thermal efficiency of system.The T/P92 steel has excellent comprehensive performances than T/P91 steel, has been subjected to the common concern of countries in the world and has obtained application in developed country's coal fired power plant, and the U.S. included the P92 steel in its ASME standard in 2002 simultaneously.Huaneng Group 4 * the 1000MW of Yuhuan power plant unit, four large pipelines that China builds up have used the P92 steel, and Zou County, Shandong power plant, Changshu, Jiangsu power plant etc. has also adopted the T/P92 steel in its expansion project.And along with China's unit develops to high efficiency, big capacity, high clean coal technique direction, in the maintenance and renovation and new power plant construction of the old power plant of China, the widespread usage of novel martensite refractory steel T/P92 will be an inexorable trend from now in expectation.
Develop that every performance indications reach or near external like product level and the T/P92 steel is complementary, low-cost welding material, change the present situation of the complete dependence on import of T/P92 steel welding material, realize the production domesticization of T/P92 steel welding material, not only can save a large amount of foreign exchanges for country, and, have important practical significance and remarkable economic efficiency to advancing the extensive use of T/P92 steel in China power station.
Relevant patent and bibliographical information are not seen in the development of the ultralow hydrogen basic electrode of calcium oxide slag system P92 steel at home and abroad as yet.
Summary of the invention
The objective of the invention is to solve the prescription problem of P92 welding rod, because the T/P92 steel is to work under HTHP, alloy content is higher and have certain crackle to be inclined to, so require the electrode coating slag system can guarantee that the core wire composition has higher recovery, can guarantee that again the weld metal impurity content is few, hydrogen content is few, and crack resistance is good.Therefore, selected for use by CaCO
3-CaF
2-SiO
2The alkaline low-hydrogen type slag system of forming is as development covering of an electrode type, and the content of diffusible hydrogen in the restriction weld metal of adopting an effective measure, and makes it be limited in 5mL/100g (mercury process) with interior ultralow hydrogen scope welding rod.The invention provides a kind of calcium oxide slag system P92 steel welds with ultralow hydrogen basic electrode (being called for short the P92 welding rod).
The invention provides a kind of P92 steel welds with ultralow hydrogen basic electrode, it is characterized in that electrode coating is for containing following substances by mass percent: 1~7% ferromanganese, 4~9% ferrosilicon, 1.5~2.5% aluminium, 3~8% nickel powders, 1~4% quartz, 3~6% ferro-niobiums, 0.5~1.0% vanadium iron, 4.5~6% titanium dioxides, 20~30% fluorites, 40~60% marbles.
Wherein the effect of each composition is as follows:
Ferromanganese: deoxidation, transition metal manganese in weld seam plays the welding seam alloying effect, and it mainly acts on also is to strengthen the intensity that improves weld metal.Mn can reduce austenite to ferritic phase transition temperature, suppresses austenite phase transformation to pro-eutectoid ferrite and ferrite side plate under higher temperature, promotes the formation of acicular ferrite, when improving weld metal intensity, improves the toughness of weld metal.
Ferrosilicon: deoxidation, transition silicon in weld seam, butt welded seam metal strengthening simultaneously.
Aluminium: deoxidation.
Nickel powder: alloying action is transition nickel in weld seam, adds a certain amount of Ni and help improving weld metal impact flexibility, offsets simultaneously because the red crisp trend of high temperature that the existence of Cu brings.
Quartzy: slag making, the viscosity of adjustment coating.
Ferro-niobium: alloying action, transition niobium in weld seam.
Vanadium iron: alloying action, transition vanadium in weld seam.
Titanium dioxide: the characteristic, stable arc and the refinement molten drop that improve slag.
Fluorite: slag making, dehydrogenation improves the viscosity of slag etc.
Marble: slag making, gas making, stabilising arc, refinement molten drop.
Thereby the main task of Welding Metallurgy be deoxidation and in weld seam the transition alloy make weld seam obtain good comprehensive mechanical properties.Because selected preferred metal powder and alloyed powder coupling, slag making, gas-forming substance and the arc stabilizer of adding appropriateness make welding rod obtain the favorable manufacturability energy; The cladding metal ingredient of welding rod and mechanical property and processing performance see Table 1, and diffusible hydrogen content sees Table 2.
The development usability of electrode can be good, compare with the import welding rod, the development welding rod have splash little, the molten bath good fluidity, slag covers evenly, and appearance of weld is careful, attractive in appearance, take off good welding procedure characteristics such as slag is easy, the deposited metal diffusible hydrogen content of development welding rod has obtained effective control, and the deposited metal diffusible hydrogen content is 1.985mL/100g, meets ultralow hydrogen standard-required.
Preparation method of the present invention adopts prior art, may further comprise the steps:
1, suppresses medication powder according to the welding rod coating recipe preparation electrode coating of development.
2, the production of welding rod is produced in electrode extrusion press, adds the medicinal powder according to the formulated of development in extrusion press, uses common welding rod to be pressed into the welding rod product with steel core H08Mn2SiA or high chrome-molybdenum steel wire rod.
The specific embodiment
All embodiment welding rods all are to be made by the common welding rod extrusion press:
1. select for use Φ 2.5 high chrome-molybdenum steel wire rods to make steel core.Get 20 gram ferromanganese, 40 gram ferrosilicon, 15 gram aluminium, 30 gram nickel powders, 10 grams are quartzy, 30 gram ferro-niobiums, 5 gram vanadium iron, 50 gram titanium dioxides, 200 gram fluorites, 600 gram marbles are totally 1000 grams and waterglass 40 grams, put into mixed powder machine and mix 10 minutes, then mixed-powder added in the electrode extrusion press.Be pressed into welding rod, welding condition is: welding rod oven dry (℃ h): 350 * 2; Preheat temperature (℃): 150~200; Interlayer temperature (℃): 200~250; Welding current (A): 110~130; Weldingvoltage (V): 25~28; Post weld heat treatment standard (℃ h): 770 ± 10 * 2~4; Programming rate (℃/h): 100~120; Cooling rate (℃/h): 120~150.Mechanical property the results are shown in Table 3, diffusible hydrogen content sees Table 4.
2. select for use Φ 3.2 high chrome-molybdenum steel wire rods to make steel core.Get 30 gram ferromanganese, 60 gram ferrosilicon, 22 gram aluminium, 38 gram nickel powders, 30 grams are quartzy, 50 gram ferro-niobiums, 6 gram vanadium iron, 50 gram titanium dioxides, 250 gram fluorites, 464 gram marbles, totally 1000 grams and waterglass 60 grams are put into and are mixed powder machine mixing 10 minutes, then mixed-powder are added in the electrode extrusion press.Be pressed into welding rod, welding condition is: welding rod oven dry (℃ h): 350 * 2; Preheat temperature (℃): 150~200; Interlayer temperature (℃): 200~250; Welding current (A): 110~130; Weldingvoltage (V): 25~28; Post weld heat treatment standard (℃ h): 770 ± 10 * 2~4; Programming rate (℃/h): 100~120; Cooling rate (℃/h): 120~150.Mechanical property the results are shown in Table 5, diffusible hydrogen content sees Table 6.
3. select for use Φ 4.0 high chrome-molybdenum steel wire rods to make steel core.Get 42 gram ferromanganese, 70 gram ferrosilicon, 25 gram aluminium, 50 gram nickel powders, 40 grams are quartzy, 35 gram ferro-niobiums, 8 gram vanadium iron, 60 gram titanium dioxides, 260 gram fluorites, 410 gram marbles are totally 1000 grams, and waterglass 80 grams, put into and mix powder machine mixing 10 minutes, then mixed-powder added in the electrode extrusion press.Be pressed into welding rod, welding condition is: welding rod oven dry (℃ h): 350 * 2; Preheat temperature (℃): 150~200; Interlayer temperature (℃): 200~250; Welding current (A): 110~130; Weldingvoltage (V): 25~28; Post weld heat treatment standard (℃ h): 770 ± 10 * 2~4; Programming rate (℃/h): 100~120; Cooling rate (℃/h): 120~150.Mechanical property the results are shown in Table 7, diffusible hydrogen content sees Table 8.
4. select for use Φ 4.0H08Mn2SiA to make steel core.Get 10 gram ferromanganese, 90 gram ferrosilicon, 25 gram aluminium, 30 gram nickel powders, 40 grams are quartzy, 30 gram ferro-niobiums, 8 gram vanadium iron, 50 gram titanium dioxides, 300 gram fluorites, 417 gram marbles are totally 1000 grams, and waterglass 80 grams, put into and mix powder machine mixing 10 minutes, then mixed-powder added in the electrode extrusion press.Be pressed into welding rod, welding condition is: welding rod oven dry (℃ h): 350 * 2; Preheat temperature (℃): 150~200; Interlayer temperature (℃): 200~250; Welding current (A): 110~130; Weldingvoltage (V): 25~28; Post weld heat treatment standard (℃ h): 770 ± 10 * 2~4; Programming rate (℃/h): 100~120; Cooling rate (℃/h): 120~150.Mechanical property the results are shown in Table 9, diffusible hydrogen content sees Table 10.
5. select for use Φ 4.0H08Mn2SiA to make steel core.Get 70 gram ferromanganese, 40 gram ferrosilicon, 25 gram aluminium, 80 gram nickel powders, 10 grams are quartzy, 60 gram ferro-niobiums, 10 gram vanadium iron, 45 gram titanium dioxides, 260 gram fluorites, 400 gram marbles are totally 1000 grams, and waterglass 80 grams, put into and mix powder machine mixing 10 minutes, then mixed-powder added in the electrode extrusion press.Be pressed into welding rod, welding condition is: welding rod oven dry (℃ h): 350 * 2; Preheat temperature (℃): 150~200; Interlayer temperature (℃): 200~250; Welding current (A): 110~130; Weldingvoltage (V): 25~28; Post weld heat treatment standard (℃ h): 770 ± 10 * 2~4; Programming rate (℃/h): 100~120; Cooling rate (℃/h): 120~150.Mechanical property the results are shown in Table 11, diffusible hydrogen content sees Table 12.
High chrome-molybdenum steel wire rod steel core composition
C |
Si |
Mn |
Cr |
Mo |
V |
0.08-0.11 |
0.20-0.50 |
0.32-0.56 |
8.0-9.5 |
0.85-1.05 |
0.18-0.25 |
Table 1 cladding Metal Mechanic Property and processing performance
The diffusible hydrogen content (mL/100g) of table 2 welding rod deposited metal
Sample |
1 |
2 |
3 |
4 |
Mean value |
Content |
1.27 |
1.47 |
2.57 |
2.63 |
1.985 |
Table 3 cladding Metal Mechanic Property and processing performance
The diffusible hydrogen content (mL/100g) of table 4 welding rod deposited metal
Sample |
1 |
2 |
3 |
4 |
Mean value |
Content |
2.68 |
3.25 |
2.11 |
2.87 |
2.7275 |
Table 5 cladding Metal Mechanic Property and processing performance
The diffusible hydrogen content (mL/100g) of table 6 welding rod deposited metal
Sample |
1 |
2 |
3 |
4 |
Mean value |
Content |
0.86 |
1.39 |
1.64 |
1.77 |
1.415 |
Table 7 cladding Metal Mechanic Property and processing performance
The diffusible hydrogen content (mL/100g) of table 8 welding rod deposited metal
Sample |
1 |
2 |
3 |
4 |
Mean value |
Content |
0.78 |
1.25 |
1.34 |
1.68 |
1.2625 |
Table 9 cladding Metal Mechanic Property and processing performance
The diffusible hydrogen content (mL/100g) of table 10 welding rod deposited metal
Sample |
1 |
2 |
3 |
4 |
Mean value |
Content |
0.80 |
1.35 |
1.44 |
1.68 |
1.3175 |
Table 11 cladding Metal Mechanic Property and processing performance
The diffusible hydrogen content (mL/100g) of table 12 welding rod deposited metal
Sample |
1 |
2 |
3 |
4 |
Mean value |
Content |
0.76 |
1.26 |
1.54 |
1.72 |
1.32 |