EFFECT OF BATCH ANNEALING ON THE SECONDARY WORKING EMBRITTLEMENT OF TI-IF STEEL

摘要

The effect of two batch annealed condition (BAH and BAHN) on the DBTT of Ti-IF and Ti-IF+B steel was investigated, the following results were obtained. 1) The DBTT of Ti-IF steel treated by BAH is beneficial to SWE than BAHN, P segregation is more serious in BAHN than in BAH, the main reason is that the soaking time of BAHN is longer than BAH. 2) DBTT variance according to sample position in coil corresponds well with the nitrogen content of the sample in BAHN. Boron addition decreases the DBTT rapidly, 4ppm of B addition can reduce the DBTT about SO . But it cannot change the tendency that the DBTT of the sample in the outer position of the coil is higher than that of the inner.