Carbon steel stainless steel welding process qualification
I. Introduction. With the continuous development of industrial technology, welding technology has been widely used in various engineering fields. Carbon steel and stainless steel are common welding materials, and their welding process qualification is particularly important. In this paper, the basic concepts, evaluation methods, welding process parameters and evaluation standards of carbon steel stainless steel welding process evaluation will be elaborated in detail.
2. Overview of welding process qualification.
Welding process qualification refers to a test process carried out under specific conditions to verify the correctness of the proposed welding process. The main purpose is to ensure that the welding process produces welded joints that meet the quality requirements. Welding process qualification usually includes the following steps: selecting the appropriate welding method, determining reasonable welding process parameters, preparing the welding test plate, welding, non-destructive testing and mechanical property testing of the welded joint, etc.
3. Carbon steel stainless steel welding process qualification method.
1.Selection of welding method.
In the evaluation of carbon steel stainless steel welding process, the appropriate welding method should be selected according to the nature, thickness, structural form and use requirements of the material. Commonly used welding methods include electrode arc welding, gas shielded welding, submerged arc welding, etc. When choosing a welding method, factors such as its scope of application, welding efficiency, cost, and difficulty of operation should be fully considered.
2.Determination of welding process parameters.
Welding process parameters are important factors affecting welding quality, mainly including welding current, arc voltage, welding speed, welding wire diameter, etc. In the qualification of carbon steel stainless steel welding process, the best combination of welding process parameters should be determined through testing to ensure that high-quality welded joints are obtained.
3.Preparation of welding test plates.
The welding test plate is a test piece used for welding process qualification, and its size, material and processing should meet the requirements of relevant standards. In the qualification of carbon steel stainless steel welding process, a certain number of welding test plates should be prepared, and their appearance quality, non-destructive testing and mechanical properties should be tested to verify the correctness and reliability of the welding process.
Fourth, carbon steel stainless steel welding process parameters.
1.Electrode selection.
In carbon steel stainless steel welding, the appropriate electrode should be selected according to the chemical composition, mechanical properties and use requirements of the base metal. For carbon steel, welding rods with good deposition properties and mechanical properties should be selected;For stainless steel, welding rods with good corrosion resistance and mechanical properties should be selected. When selecting an electrode, factors such as the type of coating, the type of current, and the performance of the electrode should also be considered.
2.Welding current and arc voltage.
Welding current and arc voltage are the key factors that affect the quality of welding. In carbon steel stainless steel welding, the appropriate welding current and arc voltage should be selected according to factors such as the diameter of the welding rod, the thickness of the base metal and the welding position. Welding currents and arc voltages that are too large or too small will affect the quality of welding, so they should be adjusted appropriately in practice.
3.Welding speed.
Welding speed refers to the length of the weld completed per unit of time. In carbon steel stainless steel welding, the appropriate welding speed should be selected according to factors such as base metal thickness, electrode diameter and welding position. Appropriate welding speed can ensure that the weld is well fused and improve the welding efficiency. In practice, appropriate adjustments should be made according to the specific situation.
5. Evaluation criteria.
In the evaluation of carbon steel stainless steel welding process, the relevant evaluation standards should be followed. These standards mainly include: GB50236-2011 "Construction Code for Industrial Pipeline Welding Engineering for Field Equipment", NB T47014-2011 "Welding Process Qualification for Pressure Equipment", AWS B40 "Code for Welding of Steel Structures", etc. These standards specify in detail each link in the qualification of carbon steel stainless steel welding process to ensure the accuracy and reliability of the evaluation.