What are the specific technical requirements of welding process in the manufacture of thermos cups?

What are the specific technical requirements of welding process in the manufacture of thermos cups?
The welding process plays a vital role in the manufacture of thermos cups. It is not only related to the sealing and thermal insulation performance of the thermos cup, but also directly affects the durability and aesthetics of the product. The following are some specific technical requirements of welding process in the manufacture of thermos cups:

Selection of welding materials

1. Compatibility of welding materials
The thermos cup is usually made of double-layer stainless steel inside and outside, so the welding material must have good compatibility with the stainless steel material. The chemical composition and physical properties of the welding material should match the stainless steel material to be welded to ensure that the welded joint can achieve strength and corrosion resistance similar to that of the parent material. For example, for a thermos cup made of 304 stainless steel, a welding rod or welding wire suitable for 304 stainless steel welding should be selected to ensure the welding quality.

2. Purity of welding materials
The purity of welding materials directly affects the quality of the welded joint. High-purity welding materials can reduce impurities and defects generated during welding, such as pores, slag inclusions, etc. These impurities and defects will reduce the strength and sealing of the welded joint, thereby affecting the durability and thermal insulation performance of the thermos cup. Therefore, when selecting welding materials, products with strict quality control and high purity should be given priority.

Welding equipment and process parameters

1. Precision and stability of welding equipment

The precision and stability of welding equipment are the key to ensuring welding quality. High-precision welding equipment can accurately control various parameters in the welding process, such as welding current, voltage, welding speed, etc. For example, laser welding equipment has a high-precision positioning system and stable welding parameter control, which can achieve precise welding, beautiful welds and small deformation. Stable welding equipment can ensure that the welding quality remains consistent during a long production process and reduce welding defects caused by equipment failure.

2. Optimization of welding process parameters

Optimization of welding process parameters is an important means to improve welding quality. Different welding methods and welding materials require different process parameters. For example, in the process of argon arc welding, the welding current, voltage and welding speed need to be adjusted according to the thickness of the welding material and the welding position. Excessive welding current will cause overheating of the weld joint and thermal cracking; too small welding current will cause insufficient welding and insufficient weld strength. Therefore, it is necessary to optimize the welding process parameters according to the specific welding conditions to obtain the best welding effect.

Control of welding process
1. Preparation before welding
Preparation before welding has an important impact on welding quality. First, the welding area needs to be thoroughly cleaned to remove oil, rust and oxides on the surface. These impurities will hinder the combination of welding materials and parent materials and reduce the strength and sealing of welded joints. Secondly, the welding equipment should be inspected and debugged to ensure that it is in good working condition. In addition, technical training is required for welding personnel to familiarize them with welding processes and operating procedures and improve their welding skills.

2. Monitoring during welding
During the welding process, the welding quality needs to be monitored in real time. By observing the shape, color and fluidity of the welding pool, it can be judged whether the welding is normal. For example, if the welding pool is oval and the surface is smooth, it means that the welding current and speed are more appropriate; if the pool is too large or too small, it means that the welding parameters need to be adjusted. In addition, welding quality inspection equipment, such as ultrasonic flaw detectors, can also be used to perform non-destructive testing on welded joints, timely detect welding defects and repair them

Post-welding treatment

1. Grinding and polishing of welds

After welding, there are usually some uneven and rough areas on the weld surface, which need to be polished and polished. Grinding can remove weld nodules, weld slag and oxide scale on the weld surface, making the weld surface flat and smooth. Polishing can further improve the aesthetics of the weld and make it coordinated with other surfaces of the thermos cup. In addition, grinding and polishing can also help eliminate welding stress, reduce stress concentration in the weld, and improve the fatigue strength of the welded joint.

2. Inspection of welding quality
The inspection of welding quality is the last line of defense to ensure the welding quality of the thermos cup. Strict appearance inspection and internal quality inspection of welded joints are required. Appearance inspection mainly checks the shape, size and surface quality of the weld to ensure that the weld is free of defects such as cracks, pores, and slag inclusions. Internal quality inspection requires the use of non-destructive testing technologies such as X-ray flaw detection and ultrasonic flaw detection to check whether there are defects inside the weld. For unqualified welding joints, they must be repaired until the quality requirements are met.

Control of welding environment
1. Control of temperature and humidity
The temperature and humidity of the welding environment have an important impact on the welding quality. Excessive temperature will cause thermal expansion of welding materials and base materials, affecting the accuracy of welding dimensions. Excessive humidity will cause moisture to be generated in the welding area, resulting in defects such as pores during welding. Therefore, during the welding process, it is necessary to control the temperature and humidity of the welding environment and keep them within an appropriate range. For example, air conditioners and dehumidification equipment can be installed in the welding workshop to adjust the temperature and humidity.

2. Prevent pollution and interference
The welding environment should be kept clean to prevent pollutants such as dust and oil from interfering with the welding process. Pollutants will adhere to the welding surface and affect the combination of welding materials and base materials. In addition, external interferences such as strong winds and vibrations need to be avoided during welding, which will make the welding pool unstable and affect the welding quality. Therefore, when welding, a relatively closed welding area should be selected, and corresponding protective measures should be taken, such as setting up wind shields and shock pads.

Skills and experience of welders
1. Proficiency of welding skills
The proficiency of welders’ skills directly affects the quality of welding. Skilled welders can accurately control welding parameters and flexibly respond to various situations that occur during welding. For example, in the process of argon arc welding, welders need to master the adjustment skills of welding current, voltage and welding speed to obtain a stable welding pool and a good welding joint. In addition, skilled welders can also choose appropriate welding methods and welding sequences according to different welding materials and welding positions to improve welding efficiency and quality.

2. Accumulation of welding experience
The accumulation of welding experience is of great significance to improving welding quality. Experienced welders can predict possible problems in the welding process based on previous welding experience and take corresponding preventive measures. For example, when welding the mouth of a thermos cup, experienced welders will know how to control the welding speed and welding current to avoid overheating of the weld or insufficient welding. In addition, welding experience can also help welders quickly identify and deal with welding defects during the welding process and improve the welding yield rate.