Discussion on Welding Technology of NM360 High-Strength Wear-resistant Steel Plate
The welding of NM360 high-strength wear-resistant steel plates should be carried out in accordance with the applicable codes, such as AWS D:1.1. Based on the welding conditions and types, the selection of welding materials should be targeted. The preheating temperature for the NM360 steel plates before welding is normally around 200-300°C and the interpass temperature must be maintained no more than 350°C. Subsequent to welding, a surface pre-treatment like pickling or grinding should be performed.
Besides consumable electrode, we have to prepare the ready-for-welding materials, such as backing-clad plates and welding wire. The welding consumables should be chosen according to the application conditions, such as the plate thickness and, if necessary, the preferred deposition rate. Generally, the backing plate should be low carbon steel or low-alloy steel. And the appropriate welding wire for NM360 steel plate is ENiCrMo-3 or ENiCrMo-4 stainless steel wire in the 1.2mm or 1.6mm diameter. As for the welding current, we should select the parameters based on the corresponding welding process.
Welding of NM360 steel plate has to minimize the hydrogen content and the thermal impact on the heat affected zone (HAZ) to reduce the possibility of cold cracking. The most suitable welding technique to achieve these goals is an alternating current (AC) welding process with a stringer bead technique and small weaving angle. According to different fixture conditions and welding sizes, the welding parameters should be appropriately adjusted.
In every technological operation, it is essential to keep the welding environment clean, no rusty and oil-tainted parts should be present near the welding part. Besides, service personnel should always wear protective masks, gloves, and vests when conducting welding works.
Besides, we should inspect the post-welding parts like plate and welds to ensure their tightness. Using CT, X-ray, or ultrasonic weld inspection methods, we can automatically detect their defects.
When manufacturing parts of a large size, MT or UT test should be also used to determine if the plates show any porosity or inclination of cracks appearing on the surface of the plates or in the welds. All defects in the welding that detected using these tests should be immediately addressed for re-welding before the product further passes to the next process.
In conclusion, NM360 high-strength wear-resistant steel plates are very popular and widely used in both industry and construction applications. However, their welding technology is complicated and requires special attention and strict operating procedure to achieve a successful welding result. With knowledge of the welding process and corresponding welding materials, we could guarantee the performance and quality of the end products.
Conatct us
