The development of welding flux of agglomeration of F8P4 refractory steel reachs application

Keyword: Agglomeration welding flux (F8P4) , KEY WORD of tenacity, refractory steel: Welding flux of introductive F8P4 of SINTERED FLUX F8P4 TOUGHNESS HEAT-RESISTING STEEL is model of American agglomeration welding flux, "F " express welding flux, "F " the number from the back, show tensile strength level; "P " the mechanical function of the test after showing classics heat treatment; "P " the number from the back states concussion of frit apply metal is absorbed result the to experiment temperature requirement when not be less than 54J. F8P4 agglomeration welding flux is me machinery plant of chemical industry of company of company and industry of chemistry of Nanjing of company of Chinese petrifaction group, develop development jointly use at refractory steel of low alloy Cr-Mo to solder special welding flux. Adopted special manufacturing technology according to asking to consider, the F8P4 welding flux that development goes has sex suction tide content of content of diffusible hydrogen of metal of apply of low, frit and S, P is low, manganese burns caustic to wait for an advantage less, already substituted entrance product. The development of 1 welding flux 1.

This welding flux cooperates 1 technology index after solder of classics of H08CrMoA welding wire, welding line should reach following technology target: Express metallization of 1 frit apply to learn composition %(TABLE 1:CHEMICAL COMPOSITION OF DEPOSIT MetaL notes: X (brittleness factor) should press type calculates: X=(10P+5Sb+4Sn+AS)/100 expresses 2: Frit apply mechanical properties of metals (TABLE 2: MECHANICAL PROPERTIES OF DEPOSIT MetaL)1.

2.

Broken bits fastens first choose F8P4 welding flux is low alloy refractory steel special welding flux, solder in the process, ask the oxidation that reduces alloying element as far as possible burns caustic, welding flux should have taller alloying element to transfer coefficient, research chooses fluorine alkaline model if broken bits department is expressed 3. Express 3: Fluorine is alkaline model broken bits ties an option (TABLE 3: CHOICE OF THE SLAG SYSTEM) solders to achieve the use requirement of Cr-Mo steel, the course experiments in great quantities, if composition of affirmatory F8P4 welding flux is expressed 4. Express 4: The bases %(table 4 of F8P4 welding flux: Main Composition Of Flux) : According to alkalinity computation formula: Alkalinity of F8P4 welding flux is Bi=2.

71.

3.

Technical properties adjusts F8P4 welding flux to be basic slag department, the difficulty that adjusts technical properties is to solve " hemp is nodded " . "Hemp is nodded " call gas impress again, solder the slaggy caky rate in the process is rapid, the gaseous material of generation has not enough time to cross slaggy transgression from bath surface, stop to be mixed in bath slaggy interface, caky when metal of oppressive frit apply, impress is formed in welding line surface. F8P4 asks to have taller alkalinity, slaggy in should join the alkalescent oxide such as many CaO, MgO necessarily, a large number of CaCO3 are joined in agglomeration welding flux, increased the oxidisability of welding flux on one hand, make gas increase, generation " hemp is nodded " , soot increases, worsened technical properties; On the other hand, the CaCO3 in agglomeration welding flux is decomposed, bulk of welding flux grain sends not close pine, reduced the grain intensity of welding flux, affect the performance characteristics of welding flux. Join a large number of MgO, although improve slaggy permeability, decrease " hemp is nodded " , but MgO becomes Mg easily with water union (0H) 2, increase the amount containing hydrogen in welding flux, content of the diffusible hydrogen in bringing about frit apply metal is elevatory, make its dosage got restrict. In adjusting a process, we use a few neuter oxide (be like: Al2O3, ZrO2) will replace CaCO3 and SiO2 slagging. Basic slag is medium, caF2 content is bigger, will replace partial MgO with CaF2, replace the measure such as partial CaCO3 with a few CaSiO3, make F8P4 welding flux is in make sure Gao Jian is spent while, also obtain satisfactory technical properties. 1.

4.

The adjustment of microtherm tenacity frit apply mechanical properties of metals adjusts a process in, of the most inaccessible requirement is AKV of microtherm concussion tenacity (- 20 ℃ ) ≥ 54J, because home solders Cr-MO refractory steel asks normal temperature concussion is absorbed only result, and F8P4 is to press foreign demand, substitute entrance product, bring certain difficulty to the design so. We adopt the following measure to raise welding line low temperature to pound tenacity: (1) raw material choice: Place asks with raw material bases its purity (content) should tall, the harmful element content such as S, P wants to be controlled strictly, solder in the process, once the S in raw material, P enters bath, shuck off not easily, p is taken off harder, affect welding line directly immanent quality. (2) raise welding flux alkalinity: Alkalinity of F8P4 welding flux is taller, control is in Bi=2.

7 the left and right sides, content of diffusible hydrogen of frit apply metal and oxygen content are very low, alkalinity is taller the S in welding flux, P transfers very hard to welding line. (3) the adjustment that alloy fastens: In adjusting mechanical function process, discover alloy department adjusts the alloy with minim Ti-B-Ni to turn the result best, join minim Ti, B the distributinging configuration of the field trash in changeable welding line and effective ground refine ferrite grain, can improve the tenacity of welding line thereby. 1.

5.

Composition of welding line chemistry reachs frit apply mechanical properties of metals surely really 1.

5.

The chemical composition of metal of 1 frit apply: Experiment in great quantities via relapsing, after affirmatory F8P4 welding flux cooperates H08CrMoA classics solder, frit apply metallization learns composition and mechanical function to be as follows: Express 5: Frit apply metallization learns composition %(TABLE 5: CHEMICAL COMPOSITION OF DEPOSIT MetaL) : X=(10P+5Sb+4Sn+As)/100=(10 × 0.

01+5 × 0.

006+4 × 0.

005+0.

001)/100=15ppm1.

5.

Mechanical properties of metals of 2 frit apply (1) mother capable person: 12CrMo armor plate, norms 150 × of 300 × 20, groove form presses GB12470-90 " low-alloy steel buries standard of arc solder welding flux " requirement. (2) welding wire: Φ of norms of H08CrMoA welding wire 4.

0mm, value of actual measurement of its chemistry composition sees a table 6. Express 6: %(TABLE 6 of composition of chemistry of H08CrMoA welding wire: Power source of COMPOSITION OF WIRE H08CrMoA)(3) is characteristic: Dc receives instead (4) craft parameter: Ground floor: The others of I=450A U=32V V=360mm/min each: 300 ℃ of ≤ of the temperature between layer of I=500-550A U=32VV=420 Mm/min (4) PWHT: Press technical index demand. (5) content of diffusible hydrogen of frit apply metal: Basis GB/T3969-1995 " the diffusible hydrogen in frit apply metal determines method " requirement, use glycerine law to undertake determining, its eventuate: 0.

95mL/100g.

(6) frit apply mechanical properties of metals (TABLE 7: MECHANICAL PROPERTIES OF DEPOSIT MetaL) expresses 7 (7) hardness of frit apply metal experiments: Be in by above craft parameter 20 × the v on armor plate of 50 × 100mm at least 4, test block classics 10 ℃ of 680 ℃ ± × 6h heat treatment, determine by GB231 next hardness was nodded at 5 o'clock, the result sees watch 8(TABLE 8) . Express 8 from above test result, each index all accords with the technical index requirement of F8P4 welding flux, production lot welding flux, assess of craft of machinery plant of chemical industry of company of chemical industry of Nanjing of company of group of classics China petrifaction reachs try out, can achieve use requirement completely. 2 conclusion 2.

1. The F8P4 of development buries arc to use welding flux of refractory steel agglomeration, technical properties, physico-chemical performance is good, achieve design requirement. 2.

2. F8P4 welding flux, content of diffusible hydrogen of frit apply metal is low, brittleness transition temperature is inferior, can satisfy the requirement that apply solder, after batch is produced, via chemistry of Nanjing of company of Chinese petrifaction group machinery plant of industrial company chemical industry is used, the result is favorable already substituted entrance product, save foreign currency CNC Milling CNC Machining