Problems with welding rods
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As the title suggests, where do welding rod grades such as J427, J507, A102, and so on come from? Which standard defines them? Aren’t the welding rod standards nowadays all based on national standards such as GB5117 and GB5118? The model numbers are of the form E5015, E4012, and so on. Then why do many drawings specify codes like J422, J427, J507, and so on?
The electrode model is the electrode number specified in the standards, while the grade is the industry-specific number for electrodes uniformly defined by the former Machinery Industry Committee in the \"Welding Materials Product Catalogue\". The difference between them is that the grade does not include a number indicating the welding position.
Why isn’t it written according to **standards** on the current drawings? Is there an industry standard for welding rod numbering?
Reply to 1# wy2652: Check page 40 of GB150; there information on welding electrodes there
The type of welding rod is **standardized; its designation includes information such as the type of coating, the type of alloy, strength, and the welding power source suitable for use.** The grade number is a code assigned by the manufacturing company itself. However, a welding rod model usually includes two to three types of welding rod grades; if the specifications in the drawings are detailed, the grade will be specified directly. Look at JB/T4708 and JB/T4709.
It seems that many welding electrodes are based on American standards
HG20581-1998 stipulates as already stated in the \"Rules for Selection of Materials for Steel Chemical Storage Vessels\": J422 is equivalent to E4303, J507 is equivalent to E5015, and so on. The welding rod standards have been revised with reference to the American AWS welding material standards; the standards now require that the grade of the welding material be indicated on design drawings and documents, rather than the model number according to national standards.
J422 etc. are grade designations, while E4303 is the model number (in reality, they refer to the same type of welding rod). When welding pressure-bearing equipment nowadays, in addition to the welding rod standards complying with national standards GB5117 and GB5118, they must also meet standard JB/T4747, due to the different requirements for P and S.
J422 is a grade from the old standards; it corresponds to the current E4303. Similarly, J507 corresponds to E4315.
This post was last edited by zgj2405 on 2010-12-18 at 16:44. J422 is the grade of the material, while E4303 is the model number; they actually refer to the same thing, it’s just that the naming conventions differ. It’s correct to use either J422 or E4303. You can refer to JB4708–4709 for information on the welding electrodes suitable for these materials.
Why isn’t it written according to **standards** on the current drawings? Is there an industry standard for welding rod numbering?