Because of the change of temperature, the manufacturing method of some of our projects needs to be changed. Because the temperature is high or low, it is easy to affect many things. HJSD steel structure is the same, so what should be paid attention to in winter steel structure welding production method?

(1) When installing the steel structure under negative temperature, attention should be paid to the deviation of the overall dimension of the steel structure caused by the temperature change.If the steel structure is constructed at normal temperature and installed at negative temperature, measures should be taken to adjust the deviation. 

(2) Q235 steel, 16Mn, 15MnV, 16Mnq and 15mnvq steel should be accepted for steel to be constructed at negative temperature.The impact toughness of steel shall be guaranteed.Q235 steel shall have – 20 ᦇ 176; D, and others shall have – 40 ා 176; D qualified guarantee. 

(3) the welding rod and welding wire for steel structure welding under negative temperature shall be selected. On the premise of meeting the preset strength requirements, the low hydrogen type welding rod with low yield strength and good impact toughness shall be selected. High toughness ultra-low hydrogen type welding rod can be accepted for important structures. 

(4) The alkaline welding rod must be baked according to the provisions of the factory certificate before use.After baking qualified, it should be stored in 80-100 ා 176; D oven, taken out when using, put it in the heat preservation cylinder, and take it out at any time.The electrode exposed for more than 2 h under negative temperature shall be baked again.The baking times of welding rod should not be more than 3 times. 

(5) the welding flux must be baked according to the provisions of the factory certificate before use, and its moisture content shall not be greater than 0.1%.When welding at negative temperature, the interval between repeated use of flux shall not exceed 2 h, otherwise it must be baked again. 

(6) The purity of carbon dioxide for gas shielded welding should not be lower than 99.5% (volume ratio) and moisture content should not exceed 0.005% (weight ratio).When using bottled gas, stop using when the pressure in the bottle is lower than 1n / mm2.When using at negative temperature, check whether the bottle mouth is frozen and blocked.

(7) High strength bolts and ordinary bolts shall be provided with product qualification certificates. High strength bolts shall be retested for torque coefficient and axial force under negative temperature, and can be used only after meeting the requirements.

(8) the coating used for steel structure shall meet the functional requirements of brushing under negative temperature, and water-based coating is prohibited.

 If you want to know more about HJSD steel structure, please pay attention to our official website