化工用英语怎么说

"化工" (huà gōng) in English is "chemical engineering". The term "chemical engineering" comes from the field of engineering that applies the principles of chemistry, physics, mathematics, and economics to design, develop, and operate processes and equipment for the production of chemicals, fuels, and other products.

Examples:

"He is studying chemical engineering at the university." (他在大学里学习化工。)
"She works as a chemical engineer at a chemical plant." (她在化工厂担任化工工程师。)
"The company is looking to hire a chemical engineer to develop new processes." (公司正在寻找雇佣一名化工工程师来开发新的工艺。)