Chamfer of diversion of turbine static lamina the filling solder of weld defects

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The article the weldability proceed with from analytic ZG20CrMo material, made reasonable turbine static lamina cast the measure of filling solder technology of blemish, assured to solder quality, satisfied use requirement. Turbine is one of important equipment of the heat and power plant, turbine lamina is all in all component of mechanical energy of translate into of heat energy of steam of high temperature of turbine lieutenant general, working environment is extremely complex. Some power plant is aircrew of 2 × 135 MW, in the crock inside middling pressure of aircrew of 2# of the discovery when construction site is checked chamfer of diversion of static lamina of the 7th class has incomplete fusion drawback, static lamina material is ZG20CrMo character, blemish is intermittent irregular shape, overall length has 1000mm left and right sides, most in amount to 5mm left and right sides. To do not make its discard as useless, shorten the time of the maintenance that return a factory, manufacturer decides with me the unit uses filling solder method to undertake remedying to its jointly in construction site. The high temperature long-term strength that the lamina after repairing should achieve a design to ask and be able to bear or endure corrode sex, strict control solders be out of shape, but blemish distributings on static lamina range is big, show semicircle arc shape to distributing, blemish deepness is inhomogenous, at the same time because static lamina appearance is irregular, the spot does not have requirement of the heat treatment after solder, increased to fill the difficulty that the solderer makes. 1, the weldability analysis ZG20CrMo of ZG20CrMo belongs to pearlite refractory steel, weldability is still good, the main problem that in soldering, exists is the sclerosis of area of cold crack, hot influence, bate, and high temperature uses medium reheat crackle for a long time. Element of the Cr in ZG20CrMo steel, Mo can raise the rigid of temper by dipping in water of steel significantly, soldering hot input spends a hour, hot influence area is easy strong organization of occurrence temper by dipping in water; Solder when hot input is too big, grain of hot influence area is apparently thick change. When content of the diffusible hydrogen in welding line exorbitant, solder when hot input is lesser, as a result of the action of strong organization of temper by dipping in water and diffusible hydrogen, be in easily solder cold crack appears in contact. Can use low hydrogen welding rod, attention to groove clears and be controlled solder hot input is in likely range, will avoid generation to solder cold crack. Reheat crackle goes out to solder now the area of thick any crystalline substance of hot influence area, with solder craft and solder leftover stress is concerned. Avoid the measure of reheat crackle: 1) employ capable person of mother of prep above of high temperature plasticity solder material; 2) avoid to stay in sensitive temperature interval longer. Control the content of harmful impurity element and cleared impurity strictly at the same time, reduce the temper brittleness of ZG20CrMo steel. 2, solder method and material are located in because of blemish surely really inside diversion chamfer, to filling the claimed accuracy of solder is very tall. The weldability that passes pair of ZG20CrMo steel is analysed and link the site actual condition, via considering to decide to be opposite crackle uses heat source concentration, heat to affect an area small, solder the tungsten with small thermal strain extremely filling solder of argon arc solder, to blemish relatively in use face of render of solder of arc of tungsten pole argon and fill of manual arc welding, lid solder method. The place of weld defects is shown 1 times like the graph. Graph the place of 1 weld defects because turbine static lamina is big, appearance is irregular, in construction the spot cannot undertake solder postheat is handled, should have from the lamina after solder at the same time be able to bear or endure admirably the angle that corrode sex, higher intensity, plasticity and hot strong performance, wearability and good solderability and precautionary reheat crackle appear sets out, the decision uses ErNiCr-3 welding wire and A507 welding rod. 3, the preparation before solder finds out blemish position first with method of chromatic flaw detection. Clear to grinder with horn blemish (do not need to get stop crack aperture) . The member that repair grizzle asks to be the skilled worker worker that has certain experience, burnish asks by shallow into deep, slow undertake, till keep clear of blemish completely. What should prevent to destroy other place when cleared blemish is bright and clean degree. Change of appearance of welding line groove is slow, groove type should make sure with be in the circumstance of welding line quality falls, fill metal as far as possible little, decrease welding stress and be out of shape, operate principle of handy easy behavior. Install dial gauge monitoring to solder be out of shape. 4, filling solder craft because turbine static lamina is big, appearance is irregular, in construction the spot cannot have heat treatment, technical personnel decides to use cold welding technology, control solder wiring energy strictly, decrease solder be out of shape. Solder adhere to to prevent to splatter in the process go up in foliaceous bar or surface of lamina of electric arc cut, need to use balata skin to enclothe soldering all round place. Solder craft parameter is shown like subordinate list place. 5, meticulous burnish should undertake to welding line after solder of the burnish after solder, cannot injury and other place. The welding line after burnish cannot prep above is same horizontal place surface. 6, after solder examining after solder, to filling solder place is reached all round undertake according to the requirement inside 20mm limits chromatic examine. Chromatic examine by " JB/T 4730-2005 " the standard undertakes. 7, last word classics is chromatic examine with ultrasonic, filling solder place flawless or other blemish, static lamina is not had be out of shape, dimension accords with a requirement, filling solder succeeds, solved production to be badly in need of. The static lamina after filling solder is successful is shown 2 times like the graph. This equipment already ran more than 3 years, did not discover unusual, prove this filling solder craft is successful. Graph the 2 static lamina that repair a success CNC Milling