Influence of Carbon Migration and High Temperature Performance in Manhole Welding

Influence of carbon migration and high temperature performance in manhole welding. When dissimilar steel welded joints are subjected to post-weld heat treatment or work at elevated temperatures, carbon migration occurs near the fusion line, resulting in a decarburized layer of low-carbide-forming elemental pearlitic steel, and adjacent chromium-nickel austenitic welds Carburized layer.

Various pipe and straight sight glass installations, all presses {Shu centerline pipe length, with "m" unit of measurement, not deducted length of various pipe fittings and valves. In addition to cast iron pipes, pipe installations are included in the value of pipe installations and assemblies. Socket cast iron pipe and straight speculum installation specifications are not listed in the joint section, their value should be calculated separately for the dose design, the rest unchanged. Steel pipe welding digging eyes to take over the work, the integrated quota, fixed should not be calculated separately.

As a result of both design and manufacture, based on the design thickness to increase the thickness to ensure the formation of thickness, and the added value of the quantifier delta (delta (1 + 2) can not be fully reflected in the design and calculation, it is necessary to propose the minimum thickness requirements of drawings, designers The nominal thickness and the formed minimum thickness should be marked on the drawing respectively, so that the production unit can determine whether to increase the production thinning amount according to the production process design and the original design of the roundness. The formed minimum thickness refers to the standard for calculating the thickness and the minimum thickness value element and the thickness of the specified corrosion allowance.