铝合金厚板精整与预拉伸(1)

Finishing and prestretching of aluminum alloy heavy plates(1)

在铝合金厚板生产中，下游工艺——精整（锯切、切边、剪切、固溶处理、退火、矫直、检验、包装等）起着重要的作用，其中固溶处理与矫直是最为关键的。所有的厚板都要经过拉伸矫直，所以它决定了厚板的生产能力；固溶处理的生产能力决定了热处理可强化铝合金厚板的通过量。预拉伸目的是尽可能地消除板材中的淬火残余应力，拉伸永久变形量0．5％可消除80％左右残余应力，此后增大拉伸量其残余应力的下降速度极为缓慢，达2％时，残余应力几乎不再下降，所以拉伸永久变形量通常为1％～3％；而用压缩法消除残余应力时，压缩永久变形量为1％一5％。当要求板材具有严格的平直度时，在拉伸后还可进一步对局部进行冷加工矫正。全文分为两篇刊出，本篇为第一篇，主要论述铝合金厚板精整工艺中的锯切、剪切、矫直等方面的内容。

In production of aluminium alloy thick plates,its downstream process-finishing, such as sawing, edge cutting, shearing, solution treatment, annealing, levelling, inspection, and packaging, etc. , plays an important role, among which the solution treatment and level- ling are the most critical. All heavy plates have to go through the process of levelling by stretching, so it determines the capacity of producing the heavy plates, and the capability of the solution treatment decides the throughput of the aluminum alloy heavy plates which can be strengthened through heat treatment. The purpose of prestretching is to eliminate the resid- ual stress as much as possible after quenching of the plates. 0.5 % of the permanent strain of stretching is able to remove about 80% of the residual stress. However,the speed of removing the residual stress becomes particularly slow by further increasing the stretching strain, and when 2% of the stretching strain is reached, the residual stress almost no longer decreases. Therefore,the normal permanent strain range is 1% -3%. While the compression method is used to eliminate the residual stress, the compression permanent strain range is 1% ~ 5%. When the plates are required to be strict in flatness, straightening by cold processing after stretching can be further used on partial areas. The whole paper will be issued in two sec- tions, and this is its first one, which mainly discussed the finishing process of aluminium alloy heavy plates, such as sawing, cutting, and straightening.