Mesurau atal:
a. Tynnwch y staen olew, y rhwd, y dŵr a'r rhuthr o'r wifren weldio, rhigol gweithio a'i arwynebau cyfagos.
b. Alkaline welding rods and fluxes shall be used and thoroughly dried.
c. DC reverse connection and short arc welding shall be adopted.
D.preheat cyn weldio i arafu'r cyflymder oeri.
E. Rhaid i weldio gael ei wneud gyda manylebau cymharol gryf.
a. Lleihau cynnwys elfennau niweidiol fel sylffwr a ffosfforws, a'u weldio â deunyddiau â chynnwys carbon isel.
b. Certain alloy elements are added to reduce columnar crystals and segregation. For example, aluminum and iron can refine grains.
c. The weld with shallow penetration shall be used to improve the heat dissipation condition so that the low melting point material floats on the weld surface and does not exist in the weld.
d. Welding specifications shall be reasonably selected, and preheating and afterheating shall be adopted to reduce the cooling rate.
e. Mabwysiadu dilyniant ymgynnull rhesymol i leihau straen weldio.
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. Yn ystod y tymheru, ceisiwch osgoi parth tymheredd sensitif craciau ailgynhesu neu fyrhau'r amser preswylio yn y parth tymheredd hwn.
Mesurau i atal craciau oer:
a. Low hydrogen type alkaline welding rod shall be used, dried strictly, stored at 100-150 ℃, and used when taking.
b. The preheating temperature shall be increased, the post heating measures shall be taken, and the interpass temperature shall not be less than the preheating temperature. The reasonable welding specification shall be selected to avoid brittle and hard structures in the weld.
c. Select reasonable welding sequence to reduce welding deformation and welding stress.
d. Conduct hydrogen elimination heat treatment in time after welding
Amser Post: NOV-08-2022