Structural characteristics, conditions of use should be based on the chemical composition of the base metal, mechanical properties, weldability and combined pressure vessel
 
And welding method takes into account the selection of  Welding Wires Manufacturer , if necessary, determined by experiments.
 
The performance of the weld metal should be higher than or equal to the corresponding base metal standard specifies the value of the lower limit or to meet the design requirements of the

technical conditions
 
Requirements.

All kinds of steel weld metal requirements are as follows

The Welding Consumables standard or product samples listed on the performance welding consumables melting performance of the deposited metal (excluding base metal), while the welding
 
The joint performance depends on the weld metal (including welding; the material deposited metal and base metal) and welding process, there is no any welding
 
Material role in the welding process can change the performance in the heat affected zone of the welded joint, from the selection of welding material.
 
Only consider the performance of the weld metal, in order to ensure the performance of welded joints will be welded process (especially post-weld heat treatment, heat input)
 
Cooperation. JB/T4709-2000, in principle, provides that "the performance of the weld metal should be higher than or equal to the the standard specified value of the corresponding base material

under
 
Limit or to meet the technical conditions prescribed pattern requirements "as a general principle of selection of welding materials:
 
The JB/T4709-2000 will GB in 150 low-alloy steel according to their performance is divided into strength low-alloy steel, heat-resistant low
 
Alloy steel and low alloy steel, low temperature so that the division actually adapt their welding characteristics.
 
Some people think that the assessment by the welding process, the welding material, "this argument is not comprehensive - for example, welding
 
16MnR steel, the following electrode welding procedure qualification: J506, J507, J507R, J507G, J507RH,
 
J507DF ...... but welding products which grades will have to consider many other factors, such as: (1) from the welding equipment to consider, J506 make
 
AC welder, J507 DC welder; â‘¡ from the crack resistance consider J507RH better than J507 welding inside the container; C
 
From labor protection considerations, J507DF (low dust) is superior to J507; (4) improve efficiency considerations, iron powder electrode J507Fe better than
 
507. After comprehensive consideration of the above factors ultimately determine the electrode grade.