NM400 wear-resistant steel plate is the most commonly used wear plate with the advantages of high wear resistance and low production cost, but its wear resistance was greatly decreased after cutting, welding and heat forming, it can only regain hardness or hardness has been decreased significantly through repeated hardening. Wear block welding is the last procedure for cylinder processing, it can not be quenched after welding or not easy to implement.

NM400 wear resistant plate hardness dropped heavily when it was heated to 250 degrees through the experiment. The cylinder made with NM400 wear resistant plate failed to work after three months only due to waste rock and other medium factors, a large area of the end plate and fan blade was peel off, which resulted in cylinder wear failure. So the mining enterprise has to repair the cylinder after lifting and it has seriously affected the normal production. However, products has been greatly improved since chromium carbide overlay wear resistance steel plate was used instead and was recognized by all of the users.