Time of preheating green laser pointer depends

Time of preheating green laser pointer depends
Knife-like corrosion referred to as the knife eclipse, it is welded to a unique joint intergranular corrosion occurs only in the welded joints of austenitic stainless steel containing Ti, Nb and

stabilization elements. Corroded areas along the fusion line, in the overheated zone of HAZ due to the region is very narrow (electric arc welding is generally by 1.0 ~~ 1.5mm), shape like Daoxue

incision, it is known as the knife-like corrosion. The high temperature overheating and temperature sensitivity of welded joints overheated zone of an important condition of the knife corrosion.

Knife corrosion causes chromium depletion layer caused by Cr23C6 precipitated. Austenitic stainless steel containing stabilizers, most of the carbon in the steel and of Ti, Nb, the formation of

TiC, NbC. The commission of green laser pointer also plays the important role.
Welding temperature over 1200 ℃ overheated zone, titanium and niobium carbides dissolved in solid solution. The effect of high temperatures, because of the diffusion capacity of carbon, dissolved

carbon can rapidly migrate to the grain boundary segregation near the grain boundaries after cooling was oversaturated, due to diffusion of titanium and niobium ability to stay in intragranular. If

the welded joints in the sensitizing temperature range again heated, the supersaturation of carbon in the austenite grain boundaries Cr23C6 form of precipitation, Ti, Nb, 17 Harbin Institute of

Technology in the austenite phase diffusion is very slow, very difficult to migrate to the grain boundary and the carbon again, so that of Ti, Nb, lost the role of a stabilizing element, the grain

boundary to form a chromium depletion layer, will have a knife in the corrosive medium under the action of erosion. green laser pointer can be utilized in camping.
Knife corrosion prevention measures to reduce the carbon content of the parent material. This is an effective measure to prevent the knife erosion, such as low carbon austenitic stainless steel

welded joints will not produce the knife corrosion. Reasonable welding process. Under the premise of ensuring weld quality, try to choose a smaller heat input, in order to reduce the overheated

zone residence time at high temperature, taking care to avoid the "temperature sensitive" of the results generated in the welding process; double-sided welding, and corrosion media contact with the

weld should be the last welding, such as can not be implemented, it should adjust the welding parameters and weld shape, try to avoid contact with the corrosive medium overheated zone once again

heated by the sensitized, as shown in Figure 5; welding process using the method of forced cooling after welding, the weld rapid cooling. green laser pointer is utilized to observe the star they

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