English
Should be based on the chemical composition of the base metal, mechanical properties, welding performance and pressure vessel combined with the structural characteristics of the use of conditions and welding methods to consider the choice of welding materials, if necessary, through the test to determine. The performance of the weld metal shall be higher than or equal to the lower limit of the corresponding base material standard or meet the technical requirements specified in the drawings.Welding Consumables
The weld metal requirements for the various types of steel are as follows: The properties listed on the welding material standard or the product samples are the properties of the welding consumables (excluding the parent metal), and the weld joint performance depends on the weld metal (including welding; Metal and metal base metal) and welding process, there is currently no welding material in the welding process can be applied to the welding joint in the heat affected zone and change its performance, from the choice of welding materials can only consider the weld Metal performance, in order to ensure the performance of welded joints need welding process (especially after welding heat treatment, line energy) with. JB / T4709-2000 principle stipulates that "the performance of the weld metal should be higher than or equal to the corresponding base material standard value of the lower limit or meet the specifications of the technical requirements."Welding Consumables
For the pressure vessel, the mechanical properties of the welded joint is the basic performance, and for the carbon steel and low alloy steel, the weld metal strength and the base metal strength is the pressure vessel industry and the welding industry "hot", research Much controversy. Weld metal and base metal mechanical performance matching should be considered to consider the strength of matching, plastic matching and toughness matching; for low-alloy steel strength by "equal" principle selection of welding materials, welded joints can have sufficient toughness reserves, and appropriate "super Strong "is also conducive to improving the anti-brittle fracture properties.Welding Consumables
Usually according to the name of the deposited metal to ensure the value of welding materials used, and the actual strength of deposited metal and often exceed the nominal value of many, such as the consideration of metallurgical factors or the role of fusion ratio, the actual weld metal strength will be far Far higher than the nominal value of the welding material deposited metal. Desire is "low strong" match, the reality may be "strong"; desire is "strong", the reality may be "super". The matching problem must be analyzed according to the actual strength level of the weld.Welding Consumables
