I’d like to ask gently: regarding the requirement for a welder’s certification, when welding Fe4 and Fe2 materials, can a welder who only has a certification for Fe4 carry out this welding work?

The qualification certificates held by welders are classified according to the type of welding material. If a welder only has Fe4 welding qualifications, it is theoretically intended for a specific type of material. Fe4 and Fe2 may represent two materials with different properties or compositions. Generally, the restrictions on welding qualifications are in place to ensure that welders have sufficient knowledge of the properties of the welding materials, thereby guaranteeing welding quality. If a welder only holds a Fe4 qualification certificate, and the workpieces are both Fe4 and Fe2, it becomes a question of whether he possesses the knowledge and skills necessary to weld Fe2 material. From a strict perspective, welding should not be carried out in theory if there is no corresponding welding qualification for the Fe2 material, as this could affect the quality and safety of the welded joint. However, in practical applications, whether welding is possible depends on the following factors: 1. **Similarity of welding materials**: If Fe4 and Fe2 are very similar in terms of chemical composition and physical properties, then welders with qualifications for working with Fe4 may be able to handle the welding of Fe2 materials to a certain extent. But this needs to be assessed and confirmed by professionals. 2. **Relevant regulations and standards**: Different regions and industries may have varying requirements regarding welding qualifications. In some cases, welding across different materials within a certain range may be permitted, but relevant regulations and standards must be followed. 3. **Employer and project requirements**: Sometimes, projects or employers may have more stringent or lenient requirements regarding welding qualifications than the standards. In this case, it is necessary to follow the specific requirements of the project or employer. In short, if one only holds a Fe4 qualification certificate and not a Fe2 qualification, the safest and most compliant approach is to avoid welding Fe2 materials, unless a clear assessment and approval are obtained confirming that such action is safe and compliant. .

Yes, stainless steel can be welded to carbon steel; a Fe4 certification for stainless steel is sufficient, while a Fe2 certification is not

Sure! Source: According to A4.3.2.1.1 in TSG Z6002-2010, once a welder has passed the welding skill test for any steel grade within a certain category, they do not need to take the welding skill test again in the following situations: (2) When a manual welder welds joints made of steel grades from this category and steel grades from a lower category ；

It cannot be overridden – per item (3) of A4.3.2.1.1 in TSG Z6002-2010, except for FelV categories, welders who use manual welding work on steel grades with lower welding category numbers

Thank you. Yes, I didn’t read the title clearly. The welder’s certificate is for Fe4; the workpieces are made of different steel types, Fe4 and Fe2, and this should be sufficient