(1) Awọn idi akọkọ fun awọn iho afẹfẹ: itri epo wa, idoti, ati bẹbẹ lọ, ati pe iye awọn iho ati ṣiṣan alulẹmu kii ṣe gbẹ, nitori ipata , abawọn epo, ati ọrinrin ninu ibora ati ṣiṣan ti iṣan-omi ti dedu sinu gaasi ni awọn irin iwọn giga. The welding line energy is too small, and the cooling speed of the molten pool is large, which is not conducive to the escape of gas. Insufficient deoxidation of weld metal will also increase oxygen porosity.
(2. Porosity is also a factor that causes stress concentration. Hydrogen porosity may also contribute to cold cracking.
a. Mu epo epo kuro, omi ipata, omi ati awọn irọlẹ lati inu waya Welle, yara yara ati awọn oniwe-to sunmọ awọn surfaces to sunmọ.
b. Awọn ọpa alurinmọni ati awọn iṣan omi ni ao lo ati ki o gbẹ daradara.
c. DC reverse connection and short arc welding shall be adopted.
D.Proheat ṣaaju ki wọn fa fifalẹ iyara itutu agbaiye.
a. Reduce the content of harmful elements such as sulfur and phosphorus, and weld with materials with low carbon content.
b. Certain alloy elements are added to reduce columnar crystals and segregation. For example, aluminum and iron can refine grains.
c. Weld pẹlu ila-kikankikan ti yoo lo lati mu ilọsiwaju isuri igbona naa ki o wa ni awọn ọna ojo oju kekere ti o dara lori dada weld ati pe ko wa ninu Weld.
d. Welding specifications shall be reasonably selected, and preheating and afterheating shall be adopted to reduce the cooling rate.
e. Adopt reasonable assembly sequence to reduce welding stress.
a. Pay attention to the strengthening effect of metallurgical elements and their influence on reheat cracks.
b. Reasonably preheat or use afterheat to control the cooling rate.
c. Reduce residual stress to avoid stress concentration.
d. During tempering, avoid the sensitive temperature zone of reheat cracks or shorten the residence time in this temperature zone.
a. Low hydrogen type alkaline welding rod shall be used, dried strictly, stored at 100-150 ℃, and used when taking.
b. Iwọn otutu ti a fifunni yoo pọ si, awọn iwọn igbona post yoo mu, ati iwọn otutu alagbegbe yoo ko kere ju iwọn otutu praheat. Alaye asọtẹlẹ ti o ni idaniloju yoo yan lati yago fun Brittle ati awọn ẹya Hard ni Weld.
c. Select reasonable welding sequence to reduce welding deformation and welding stress.
d. Conduct hydrogen elimination heat treatment in time after welding
Akoko ifiweranṣẹ: Oṣu kọkanla: Oṣu kọkanla