Weldability Index for Martensitic Steels

Martensitic steel hardens strongly during rapid cooling and tends to hydrogen cracking. The weldability index tells you how critical the material is – the higher the value, the greater the risk. Therefore, you must preheat before welding and keep an eye on the interpass temperature so that the structure does not become too hard. The exact values and the correct preheat temperature for your steel can be found in the manufacturer's data sheet.