seen bestemma stolen interstitialherdbarhet and dervid onskade sammansettningsvarianter at fran svetsbarhetssynpunkt forbettrade herdbara stole

摘要

The method according to the invention involves suitable selection of the chemical composition of the steel, the basic material being carbon manganese steel, microalloy steel and low-alloy steel, and the steel contains carbon and nitrogen and optionally boron as interstitially dissolved alloy substances, characterized in that on martensite formation in the steel transition zones a spontaneous so-called self-tempering of the said martensite is obtained when the carbon content and the nitrogen content and in the present case the boron content are chosen such that they satisfy the first equation a for boron-free steel or equation b for boron- containing steel, according to what has been set out in the patent claim, namely IMAGE or IMAGE A crucial point according to the invention is that the basic hardenability DB according to Grossmann's equation of hardenability for the ideal critical diameter has been written as IMAGE where MG is a "multiplication factor" for the influence of the particle size and MC is a multiplication factor for carbon.