H2S generation: In order to suppress the low nitrogen oxide (NOx), many power plants will use a low-nitrogen oxide boilers, and coal combustion is not fully take advantage of its special design, and the heat generated by the boiler to reduce and thus inhibit the low the generation of nitrogen oxides. But a side effect of doing due to incomplete combustion coal generating H2S. <H2S interested in the boiler wall, in particular the waterwall produce serious corrosion, the corrosion strength can be achieved annually 1.5mm-2.3mm, and for this plant requires frequent shutdown of the boiler for maintenance. 6 years, the company uses the material (ie the company INCONEL622 filler metal) ERNiCrMo-10s, and has played an outstanding role in reducing the corrosion. Traditional nickel-based welding consumables is to use the gas tungsten arc welding (Tig) low deposition rate surfacing in the boiler water wall.
2, a Copper Welding Electrodeprocess: The great wall of water surfacing workload, generally using automatic and with a dedicated program control gas tungsten arc welding process. To solve the viscous resistance of nickel base consumables in the molten state, generally torch also supplied to a slightly fast swing. Such as the use of 1.2mm welding wire flat welding, welding current about 350A, welding voltage of about 28V and pure argon for protection, the deposition rate can reach 7-8 kg an hour, while the dilution rate of the nickel alloy welding consumables very low, up to 5% -8% (ie, loss of corrosion-resistant elements in the molten pool is only 5% to 8%)
3, to improve productivity Visits an important indicator of plant efficiency: outages - maintenance cycle. When we use Welding Suppliesg consumables to prevent the the device inner wall corrosion direct result is to make the outages shorten the increase in productivity.
4, other nickel-based welding consumables: Outside addition to INCONEL622 filler metal, including INCONEL625 filler metal (or INCONEL112 electrode) the INCO-WeldC-276 filler metal, and so far, apply to most strongly corrosive environment of welding consumables: INCO-Weld686CPT From now until the end of 2005, the national power company requirements of the country in the FGD system construction production capacity has reached 18 million kilowatts (circulating fluidized bed boiler 4 million kilowatts).
1) pure copper Pure copper i.e. industrial pure copper, copper is more than 99.9%, a density of 8.9g/cm3, a melting point of 1083 ° C, with excellent electrical conductivity, thermal conductivity, is the most important electrical and thermal conductivity material. Pure copper in the annealed state high plasticity and low strength, it is suitable for a wide range of hot and cold processing. The cold working can improve the strength and hardness of the copper, lower plasticity, while the impact on the conductivity is very small, this characteristic of the pure copper makes it an important one of the
The cold hardening will reduce the recrystallization temperature of copper, pure copper for electrode welding temperature should not be higher than 150 ° C, copper rapidly softening otherwise it would affect the quality of welding. In short, the pure copper electrode is only applicable to the pressure is small, the welding temperature is low and small quantities of product. 2) cadmium copper The cadmium copper is the most important kind of electrode copper alloy material, Cd0.7% ~ 1.0%, is a heat treatment to strengthen the alloy by cold hardening to improve its hardness (up to 140HV). Cadmium copper having a good electrical conductivity, thermal conductivity and wear and resist performance, work hardening after the recrystallization temperature is low, it is only suitable for use in below 200 ℃, but also need to strengthen the welding electrode cooling in order to improve its life. 3) chromium copper Chromium copper has the characteristics of high strength and high electrical conductivity, the most widely Cr0.5% to 1.0%, the conductivity of up to 80% and 90% of pure copper, belonging to heat treatment to strengthen the alloy. Chromium after the heat treatment to diffuse form precipitates in the grain, so that the matrix to be reinforced and the conductivity is increased. Ruozai after cold working, its mechanical properties will be further improved. Higher softening temperature of chromium copper having good heat resistance, at a high temperature of 450 ~ 477 ℃ safe work, but use temperature will still prevent more than the softening temperature of the chromium copper and enhance cooling. If a small amount of silver, aluminum, magnesium and silicon, and other elements in the chromium copper formed polyhydric copper alloy, such as chromium silver, copper and chromium magnesium copper, etc., can further improve the mechanical properties and softening temperature. 4) zirconium copper Zirconium copper is a high conductivity, high thermal conductivity, heat strengthened alloy. Copper zirconium significantly improve the mechanical properties and softening temperature of the copper the common of Zr0.2% and Zr0.4% two zirconium-copper alloy. Zirconium copper aging after solution treatment and a certain degree of cold working again strengthened before higher mechanical properties and softening temperature. The use of performance superior to chromium copper and chromium zirconium copper, zirconium price is more expensive than chrome, higher manufacturing costs. 5) CuCrZr CuCrZr high strength, high conductivity copper alloy in the best performance of a heat treatment to strengthen, the high lapse strengthen both chromium copper the performance and zirconium copper the advantages of high softening temperature, so the room temperature and high temperature than high hardness. Cr0.25% ~ 0.80%, Zr0.08% ~ 0.50%, and further containing a small amount of Mg. Diffusion of Cr and CuZr particles through the solution and failure after the heat treatment, the uniformly deposited on the copper substrate to improve its performance. The small amount of Mg is added in order to improve its thermal stability. The practice shows that the use the CuCrZr made spot welding electrode welding low carbon steel or coated steel, electrode life than chrome aluminum-magnesium copper electrode increased by 5 to 10 times. 6) beryllium copper Beryllium copper is the highest strength and hardness of a copper alloy, Be2.0%. Beryllium copper after solution and aging heat treatment, its strength and abrasion resistance can reach the level of high-strength alloy steel. But the lower the electrical conductivity and the softening temperature of the beryllium copper, the use temperature exceeds 550 ° C, they fully softened, and therefore not suitable for small contact area, the high temperature of the welding surface of the spot welding or seam welding electrode, otherwise they will be conductive, thermal performance low and cause severe adhesion. 7) beryllium, cobalt and copper Beryllium, cobalt and copper is a high strength, a medium conductivity electrode copper alloy Be0.4% to 0.7% of Co2.0% to 2.8%, and the case of heat treatment to strengthen the alloy. Adding beryllium and cobalt can be formed the high melting point of the metal of high hardness Southwall composition, to significantly improve the strength of the copper, cobalt, but also improve the precipitation hardening effect of the alloy. 8) copper nickel silicon Corson copper is heat strengthened type alloy, has a high strength and hardness, good wear resistance, alternative beryllium copper as
Welding Electrode Materials, usually Ni2.4% to 3.4%, Si0.6% to 1.1%. During the heat treatment, the alloy of nickel and silicon are capable of forming an intermetallic compound and showed a diffuse phase precipitates, so that the substrate to be reinforced, so its mechanical properties and electrical conductivity is higher.