In 1992, Lincoln introduced the semi-automatic FCAW downward fastening method to the pipeline bureau, and centered on 2 fastening instrumentation combinations: Lincoln dc-400 arc welding power provide +LN23P wire feeding machine and sae-400 diesel generator arc welding power supply +LN23P wire feeding machine.In 1995, when the made use of semi-automatic FCAW downward fastening technology in national capital loop pipeline, Associate in Nursing extension was dole out in kushan plain in 1996.In the construction of Sudan project, African country project, shibuya ninglan project, lancheng Chungking project and shaanxi-beijing second-line project, this fastening method is essentially adopted for pipeline hot welding,
filling and canopy fastening.The west-to-east gas transmission project USES this method for regarding 2500 metric linear unit, and also the remaining 1500 metric linear unit is completed by automatic fastening.Nearly ten years of engineering apply has well-tried that the semi-automatic FCAW downward fastening method has been smartly promoted and employed in the development of large-diameter long pipeline.Compared with the downward fastening method beneath the protection of semi-automatic dioxide gas, the downward fastening method of semi-automatic FCAW has the benefits of fantastic process performance, stable arc, high production potency, little splash, lovely weld molding, sensible ability of steel sort and spacial position, robust wind resistance so on.
Compared with the standard downward conductor arc fastening method, it will increase the first pass rate of hot fastening, filling fastening and canopy welding to regarding 100% on the average, and will increase the productivity by one.25 to 1.About five times.Compared with automatic fastening, it's the benefits of less instrumentation investment, quick price recovery and low comprehensive cost.Welder coaching time is brief and straightforward to master.In more than 10 years of engineering construction, the standard of fastening is stable.
After X-ray scrutiny, the common pass rate of fastening joint is regarding ninety fifth to ninety eight.The use of semi-automatic FCAW downward fastening method in pipeline construction has reached the "four high" commonplace planned by the project house owners reception and abroad, that is totally appropriate for every kind of pipe diameter pipeline downward fastening method necessities.So, get owner, examine inspect, the favour of construction unit.The arc diffusion Angle of semi-automatic FCAW downward fastening is giant, leading to giant radial energy gradient of arc voltage, decreasing amplitude, light distribution and shallow penetration.
Therefore, it's not appropriate for deep penetration fastening.However, its weld forming constant is giant, splash rate is low, swish smooth weld, appropriate for pipeline downward fastening method.In the method of semi-automatic FCAW downward fastening, seven main method parameters are the foremost involved issues in fastening.These seven method parameters are arc voltage, current, wire feeding speed, wire Angle, fastening speed, thrust current and wire dry extension length.The advantages of little spatter, sensible weld molding and high production potency will be accomplished only the seven method parameters are fully matched.
Cangzhou Steel Pipe Group (CSPG)Co.,Ltd.
No.92 JieFang East Road ,Cangzhou City, Hebei,P.R.China.
CSPG has more than eighteen years history company which located in Lecong Iron and Steel World, a well-known steel distribution center in China, with superior geographical position and convenient water and land transportation.
We are a direct-selling manufacturer specializing in the research and development of spiral steel pipes, steel spiral pipes, anti-corrosion steel pipes inside and outside. Since its inception, the company has been guided by a brand-new thinking of steel pipe product market based on the business philosophy of honesty, pragmatism and knowledge-seeking.
Typical values (Weight %)
|PREN = [Cr%] + 3.3 [Mo%] + 16 [N%] ≥ 40|
Mechanical and Physical Properties
2507 combines high tensile and impact strength with a low coefficient of thermal expansion and high thermal conductivity. These properties are suitable for many structural and mechanical components. The low, ambient, and elevated temperature mechanical properties of 2507 sheet and plate are shown below. All of the test data shown are for samples in the annealed and quenched condition.
2507 is not recommended for applications which require long exposures to temperatures in excess of 5700F because of the increased risk of a reduction in toughness. The data listed here are typical for wrought products and should not be regarded as a maximum or minimum value unless specifically stated.
|Ultimate Tensile Strength, ksi||116 min.|
|0.2% Offset Yield Strength 0.2%, ksi||80 min.|
|0.1% Offset Yield Strength 0.2%, ksi||91 min.|
|Elongation in 2 inches, %||15 min.|
|Hardness Rockwell C||32 max.|
|Impact Energy, ft.-lbs.||74 min.|
Low Temperature Impact Properties
Elevated Temperature Tensile Properties
|0.2% Offset Yield Strength, ksi||80||65||61||58||55|
|Ultimate Tensile Strength, ksi||116||101||98||95||94|
|Modulus of Elasticity||psi x 106||29|
|Coefficient of Thermal Expansion |
|Thermal Conductivity||Btu/h ft 0F||8.7|
|Electrical Resistivity||W-in x 10-6||31.5|