Selection of the measurement time for the inter-layer temperature during welding
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GB/T18591-2000 specifies that the temperature of the interpass area should be measured at the weld metal or at the adjacent base metal. The temperature reading should be taken instantaneously in the welding area before the arc passes by. For example, in actual measurements, the temperature in the welding area before the arc passes can reach 240, while the temperature in the area that has just been welded a few minutes earlier drops to 130. The preheating temperature is required to be above 150, and flame heating is used for this purpose, with heating taking place simultaneously during welding. Could someone please tell me exactly when and where the interpass temperature should be measured? ? ? ?
This post was last edited by ztr1118 on 2012-3-15 07:56. I am not a welding professional, but the temperature measurement should be taken instantaneously within the welding area before the arc passes through it, so as to accurately reflect the interlayer temperature during welding.
The so-called welding interpass temperature does not refer to the center of the weld, but rather to points 50 mm away from the weld center. The preheating temperature means that during welding, the temperature at those 50 mm points must remain above this preheating temperature; there is no time limit for this. Additionally, the preheating width is generally three times the thickness of the steel plate, with a minimum of 100 mm. According to what you said, your preheating temperature is actually not sufficient, and the location of the temperature measurement point is incorrect – it should be 50 mm away from the weld center line:lol:lol:lol:lol
The so-called welding interpass temperature does not refer to the center of the weld, but rather to points 50 mm away from the weld center. As for the preheating temperature, it means that during welding, the temperature at those 50 mm points must remain above this preheating temperature at all times; there is no time limit for this. The preheating width is generally three times the thickness of the steel plate, with a minimum of 100 mm. According to what you said, your preheating temperature is actually not sufficient, and the location of the temperature measurement point is incorrect – it should be 50 mm away from the weld center line
“GB/T18591-2000 specifies that the measurement point for the interpass temperature should be at the weld metal or the adjacent base metal, and the temperature should be measured instantaneously within the welding area before the arc passes by; this is entirely correct, and measurements should be taken in accordance with these specifications. One issue is that when dealing with thick plates (over 25 mm), due to the complex heat field distribution within the welded specimen, the temperature at the measurement points fluctuates. It is only when the temperatures measured continuously (at intervals of 5–10 seconds) show a continuous decline that it can be determined that the last measured value represents the highest interlayer temperature. Due to the preheating temperature, the measurement location is specified in the standard, so it is sufficient to follow that standard. Moreover, the preheating temperature is measured after preheating but before starting welding. As soon as welding begins, the interlayer temperature should be measured at the locations specified by the standards. In fact, the preheating temperature and the interlayer temperature are essentially the same thing (abroad, these two temperatures are often indicated together, with only a slight difference in the location of measurement).
:During the handshake process, the inter-layer temperature is measured instantaneously in the welding area before the arc passes by. When taking this temperature measurement, it’s inevitable that the actual temperature value will be affected by the welding arc and end up being higher than the true temperature, isn’t that the case?
The temperature affected by the welding arc is the actual interlayer temperature that needs to be measured.
The interlayer temperature is measured instantaneously in the welding area before the arc passes by; when this temperature is measured, the actual value inevitably becomes higher than the true temperature due to the influence of the welding arc, isn’t that the case? In fact, there is no need to be so insistent on knowing the exact temperature of the welding area before the arc passed through it, as standards provide us with a benchmark. As long as we follow these established benchmarks during the evaluation process and throughout the product welding process, the actual differences can be ignored.
:Handshake, hehe, thanks for your guidance, sir.
Learned something new:):):):):):):)