Effect of rod rolling conditions on bright steel bar straightness –a study of higher straightening and lower residual stress technology of bar products I

摘要

Straightening bright steel bar products has becomeessential in the production of many mechanical parts. Recently,customers such as those associated with the automobile, precisionmachines and office automation industries, require a high degreeof straightness and lower residual stress. However, straighteningtechnology has not advanced in the past few years The goal of thisstudy is to systematically remedy this situation by developingmethodologies to attain a higher degree straightness and lowerresidual stress m bar products. In this paper, the effects of themicrostructure and the mechanical properties of a rolling rod onbar straightening were investigated. It was found that straightnesswas improved by using rods with lower and constant yield stress.These rods were produced by minimizing austenitic grain size bymeans of controlled rolling, and by controlling the ferrite-pearlitegrain size via slow cooling to attain a regular microstructure.