Good morning all teachers and students, my name is liangwenjun The topic of my report is Influence of molten salt potential on stress corrosion cracking behavior of 316 stainless steel. Stress corrosion cracking (SCC) is the cracking of sensitive materials resulting from the combined action of a fixed tensile stress and some specific corrosive medium.As shown in the picture on the right， Stress corrosion cracking is also one of the main causes of reactor structural material failure。 Structural materials for molten salt reactors must have good resistance to fluoride corrosion, excellent mechanical properties, good resistance to high temperature oxidation and irradiation Stainless steels such as 316 have ASME certification for high-temperature pile materials andare very economical.Therefore, many companies are considering 316 stainless steel as a structural material when designing molten salt reactors。Such as Kairos power and Terra power. 316 showed good corrosion resistance in purified molt en fluoride salt, and in Chen's study 316 did not crack with or without Cr addition under the synergistic effect of stress. Therefore, we accelerate corrosion by adding europium ion, and in the study to quantify the molten salt potential and stress magnitude, and finally determine the effect of molten salt potential on stress corrosion cracking of 316 stainless steel.

早上好，各位老师和同学们，我的名学是梁文军。我的报告的主题是：熔盐电位对316不锈钢应力腐蚀开裂行为的影响。

应力腐蚀开裂（SCC）是指敏感材料由固定的拉应力和某些特定腐蚀介质的结合作用导致的裂纹。如右图所示，应力腐蚀开裂也是反应堆结构材料失效的主要原因之一。

熔盐反应堆的结构材料必须具有良好的抗氟腐蚀性，优良的机械性能，良好的抗高温氧化和辐照抗性。316不锈钢具有高温堆材料的ASME认证，并且非常经济实惠。因此，许多公司在设计熔盐反应堆时考虑使用316不锈钢作为结构材料，例如Kairos power和Terra power。

316在纯化熔盐氟盐中表现出良好的抗腐蚀性，并且在陈的研究中，316在应力和腐蚀的协同作用下不会开裂，无论是否加入Cr。因此，我们通过添加欧拉金属离子来加速腐蚀，并在研究中量化熔盐电位和应力的大小，最终确定熔盐电位对316不锈钢应力腐蚀开裂的影响。

相关问题

Please introduce the following in detail: Review of existing research on analyzing metal-transfer images in GMAW process

Gas Metal Arc Welding (GMAW) is a widely used welding process in which a consumable metal wire electrode is fed into a weld pool to join two or more metal parts together. During the welding process, the electrode melts and forms a molten metal pool, which then cools and solidifies to form a welded joint.

One way to analyze the GMAW process is to examine the metal-transfer images that are generated during welding. Metal-transfer images are high-speed photographs or videos of the GMAW process that capture the behavior of the molten metal as it is transferred from the electrode to the workpiece. Analyzing these images can provide insights into the physical processes that occur during welding, such as droplet detachment, droplet formation, and arc behavior.

There have been several studies that have analyzed metal-transfer images in the GMAW process. One such study was conducted by Liu et al. (2017), who used high-speed photography to capture metal-transfer images during GMAW of aluminum alloys. They found that the droplet detachment frequency was influenced by the welding current, and that there was a critical current level above which the droplet detachment frequency increased dramatically.

Another study by Liao et al. (2019) analyzed metal-transfer images during GMAW of high-strength steel. They found that the droplet transfer mode shifted from globular to spray transfer as the welding current increased, and that the formation of an unstable arc affected the droplet detachment process.

Other researchers have used image processing techniques to analyze metal-transfer images. For example, Zhang et al. (2019) developed an algorithm to automatically detect and track the movement of droplets in metal-transfer images during GMAW. They found that the droplet size and transfer frequency were affected by the welding current and the wire feed speed.

Overall, the analysis of metal-transfer images in the GMAW process is an active area of research that has the potential to improve our understanding of the physical processes that occur during welding. By studying metal-transfer images, researchers can gain insights into the factors that affect droplet detachment, droplet formation, and arc behavior, which can in turn help to optimize the welding process for different materials and applications.

Describe the background information of GMAW process and metal transfer image in detail

### 回答1：
Gas Metal Arc Welding (GMAW), also known as Metal Inert Gas (MIG) welding, is a welding process that uses a consumable electrode wire that is fed continuously through a welding gun. The electrode wire is surrounded by an inert gas shield, typically argon or a mixture of argon and carbon dioxide, that protects the weld pool from contamination and oxidation. GMAW is widely used in the manufacturing industry, particularly for welding thin and medium-thickness metals.

The metal transfer process in GMAW refers to the way in which the electrode wire transfers molten metal to the weld pool. There are four primary modes of metal transfer in GMAW:

1. Short-circuiting transfer: This mode of metal transfer occurs when the electrode wire makes contact with the weld pool, causing a short circuit that melts the wire and deposits it onto the workpiece.

2. Globular transfer: In this mode, the electrode wire forms droplets that are too large to be transferred by short-circuiting. The droplets fall into the weld pool and create a less stable and less consistent weld.

3. Spray transfer: In this mode, the electrode wire is melted and sprayed onto the workpiece in a fine, consistent stream. This mode of transfer is often used for thicker metals and produces high-quality welds.

4. Pulsed-spray transfer: This mode is similar to spray transfer, but the welding current is pulsed to control the amount of metal deposited and reduce spatter.

The metal transfer mode used in GMAW depends on a number of factors, including the welding current, electrode wire diameter, electrode wire composition, shielding gas composition, and distance between the electrode and the workpiece.

In terms of metal transfer image, it refers to the visual representation of the metal transfer process that can be observed during welding. By using specialized equipment, such as high-speed cameras, it is possible to capture images of the metal transfer process and analyze its characteristics. These images can provide important insights into the welding process, such as the rate and consistency of metal deposition, and can be used to optimize welding parameters for improved performance and efficiency.

### 回答2：
气体保护电弧焊（GMAW）是一种常用的焊接方法，也被称为MIG焊接。它涉及使用交流或直流电弧将金属焊丝熔化并连接在一起，同时利用保护气体保护焊缝。此过程中的金属传递图像是指在焊接过程中，金属焊丝是如何熔化和传递的。

GMAW是一种半自动或自动化焊接方法。在GMAW中，金属焊丝通过焊枪供给到焊缝区域。焊枪中的电极产生电弧，使焊丝熔化。同时，保护气体在焊缝附近被释放出来，形成一个保护气氛，防止氧气和其他杂质进入焊缝。这种保护气体通常是二氧化碳或混合气体。

在焊接过程中，金属焊丝的熔化和传递是通过电弧加热实现的。电弧加热使焊丝熔化，并形成一股离子化的等离子体。离子化的气体形成了高温的焊接池，同时它们也用于将熔融的金属焊丝传递到焊缝中。金属焊丝从焊枪中缓慢传送，以保持稳定的焊接过程。

金属传递方式有三种：喷溅传递、滴落传递和冷喷传递。喷溅传递是指金属溅出焊丝并通过离子气流抛射到焊缝中。它产生了喷溅和飞溅的现象，可能影响到焊接质量。滴落传递是指焊丝逐渐融化并滴落到焊缝中形成焊点。冷喷传递是指熔化的金属焊丝被离子气流带走，形成了一个冷焊粒。

不同的金属传递方式对于不同的焊接应用有不同的优缺点。选择合适的金属传递方式可以提高焊接质量和效率。

总之，GMAW是一种常用的焊接方法，它涉及焊丝的熔化和传递，通过使用保护气体确保焊接质量。金属传递方式取决于焊接应用的要求和选择。