What kind of welding rod does Q345 steel use?
Ordinary welding rod can be, Q345 steel weldability is better.
First of all, Q345 is divided according to yield strength. Q is the code of yield. It is equivalent to the previous 16Mn. The hardness of Q345 is below HB180. The hardness of the oil after the cold is at most 200HB or so, because he is low alloy, carbon content of about 0.16, so the basic quenching has little effect.Speaking of the impact area and the hardness after welding, the carbon content of Q345 is greater than 0.45%, so the welding process is strict, and the welding of Q345 steel in the cooling process, the heat affected zone formed more easily quenched martensite, so the weld hardness increases, the ductility decreases. As a result, cracks occur after welding
Weldability of Q345 steelQ345 low alloy high strength structural steel with carbon content of 0.18% ~ 0.20%, tensile strength equal to 470-630MPa. Q345 steel alloy content is less, good weldability, welding generally without preheating.But because the Q345 steel hardened tendency is slightly larger than the low carbon steel, so at low temperatures (such as winter outdoor operations) or welding in high rigidity, large thickness of the structure, in order to prevent the cold crack, need to take measures to preheat. The preheating temperature of 16Mn steel at different plate thickness and different environmental temperature is shown in table 8.Q345 steel welding should be used in E50 type electrode, such as E5015, E5016 for alkaline electrode, the structure is not important, also can choose E5003, E5001 acid electrode. For the weldment with small thickness and narrow groove, E4315 and E4316 welding electrodes can be used.Table 8 preheating temperature of welded Q345 steelThickness of weldment (mm) preheating thermometer at different temperatures (DEG C)More than 16 of not less than of-10 DEG C - C without preheating preheated to 100 to 150 DEG C16 ~ 24 of not less than 5 DEG C 5 DEG C without preheating preheated to 100 to 150 DEG C25~40, not less than 0 degrees Celsius, not preheated, 0 degrees below 100~150 preheating temperatureMore than 40 are preheated 100~150 degreesSubmerged arc welding of Q345 steel H08MnA welding wire with flux HJ431 (open I butt welding wire with flux HJ431) or H10Mn2 (plate groove butt), when the deep groove weld of thick plate welding, welding wire with flux HJ431 H08MnMoA should be used.Q345 steel is the most widely used low alloy steel in our country at present,
