定襄县乡镇企业调查

乡镇企业的迅速发展,对于调整产业结构、开发利用本地资源、振兴经济、提高人民生活水平都起着十分重要的作用。党的十一届三中全会以后,山西省定襄县乡镇企业有了迅速的发展,从1978年的850个乡村企业发展到1986年的1630个,增加了近一倍;从业人员从一万人发展到14300人,增长了40％;总产值由1879万元发展到5258万元,增长了1.8倍,占全县工业总产值的42.6％。定襄县乡镇企业的特点是:

结构优化 组织创新

定襄锻压业存在着分布分散化、规模小型化、产品单一化、粗放化和初级化、污染严重等问题。为此应抓住环境治理这一契机 ,正确处理好外延与内涵、个体与群体、纵向延伸与横向延伸的关系。以改造升级、管理创新、规模扩张为重点进行生态化改造 ,加强市场竞争力 ,重铸辉煌。

Ductility improvement methods for commercial AZ31B magnesium alloy in cold forging

In order to realize cold forging of magnesium alloys in practical application,some methods for ductility improvement of a commercial wrought AZ31B magnesium alloy(Mg-3%Al-1%Zn,mass fraction) at room temperature were suggested.The effects of heat treatment before forging and hydrostatic pressure during forging on the ductility were investigated in cold upsetting and cup forging.High-temperature annealing was effective to reduce the degree of the texture anisotropy of the specimen,and it was found that the forging limit of the annealed specimen was improved in cold forging.On the other hand,cold cup forging of the annealed specimen was carried out with applying counter pressure.By applying counter pressures of 100-200 MPa during forging,the critical punch stroke for forging limit of the specimen without crack was improved by 25%in punch stroke.