Welding Performance of HARDOX 400 Steel Plate

HARDOX 400 steel plate, known for its high hardness and strong wear resistance, can be successfully welded as long as proper procedures and precautions are followed. Although its hardness of approximately 400 HBW enhances durability, it also makes the material more sensitive to heat input during welding. Therefore, controlling welding parameters is essential to maintain both structural integrity and wear performance.

One of the key characteristics of HARDOX 400 steel plate is its good weldability with the right techniques. The steel’s chemistry, which includes carefully controlled levels of carbon, manganese, chromium, and boron, allows it to respond well to standard welding methods such as SMAW, GMAW, FCAW, and SAW. However, because higher hardness increases the risk of hydrogen cracking, preheating is often recommended, especially for thicker plates. Typical preheat temperatures range from 100°C to 150°C depending on thickness and ambient conditions.

Controlling heat input is another crucial factor. Excessive heat can soften the heat-affected zone (HAZ), reducing the plate’s wear resistance. Therefore, low to moderate heat input combined with controlled interpass temperatures helps preserve the material’s mechanical properties. Using low-hydrogen welding consumables further minimizes the risk of cracking.

Post-weld heat treatment is generally not required, but slow cooling is important to prevent temperature shock and preserve toughness. Welders should also avoid overwelding, which may introduce unnecessary heat that can weaken the HAZ.

When these guidelines are followed, HARDOX 400 steel plate offers reliable and durable welded joints suitable for demanding applications such as mining equipment, truck bodies, structural reinforcements, and wear-resistant components. With proper technique, the steel maintains strong performance while ensuring safe and long-lasting weld integrity.