nigrescence meaning in English
n.
变黑；(颜色；皮肤；眼睛等的)发黑。
Examples
- Carbon channel is usually finished with electro - galvanization . hot dipped galvanzined finish or epoxy coating or nigrescence is also available on special order
碳钢型钢的表面处理普通为电镀，如需热浸镀锌、喷塑、发黑等要在订货时说明。 - Reshi chemicals is a specialist in manufacturing and distributing metal surface treatment reagent : phosphorus treatment reagent , water treatment reagents , electro - plating additive reagents , normal temperature nigrescence reagent , pre - treatment reagents , etc
是一家专业从事金属表面处理药剂：磷化处理药剂、水处理剂、电镀添加剂、钢铁常温发黑剂以及前处理产品的生产商和代理商。