and 6a to 9a are in accordance with the invention example 10 is given by way of comparison examples 1 to 9 illustrate the combined effect of the content in terms of carbon and the highly carbide producing elements for conventional contents of silicon examples 6a 7a 8a and 9a illustrate the particular effect of silicon the effect on the weldability can be evaluated in particular using a test by means of which the minimum preheating temperature is determined for the auto flange weld joint for which cracking is not seen to appear after welding this test involves producing weld seams with preheating temperatures of 150 u00b0 125 u00b0 100 u00b0 75 u00b0 50 u00b0 25 u00b0 5 u00b0 and observing the joints obtained in order to detect the presence or absence of cracks the results of this evaluation which correspond to the examples of tables 1 and 2 are illustrated in the single figure in which a first line 1 can be seen which represents the path of the minimum non cracking temperature as a function of the content of highly carbide producing elements for a silicon content in the order of 0 3 on this line it is found that when the content of highly carbide producing elements increases and the content in terms of carbon decreases.