Abstract: Quenching stripe with hardness difference problem of thin gauge wear resistant steel plates was studied by means of microstructure and hardness examination combined with equipment and process analysis. The results show that the main reasons for the problem are the different water flows and cooling rates between the groove and collar regions of spiral rollers of the quenching machine. By optimization of the quenching temperature, water flow, roller speed and roll gap, the quenching stripe problem is solved and good plate flatness is obtained.

Key words: wear resistant steel, quenching stripe, abnormal hardness, cooling rate