根据我厂几年来实践证明,10铬硅钼钒7钢管(φ42×3.5毫米)的手工气焊不易掌握。我们遵照伟大领袖毛主席关于“我们要承认困难,分析困难,向困难作斗争。”的教导,在实际工作中认真对待困难,使我们初步掌握了这种管材的气焊工艺,现简单介绍如下:焊前准备1.焊前对焊丝和坡口的锈、油等污物进行清理。2.使用合格的焊丝,如焊08铬钼钒或焊12钼铬焊丝,直径为3毫米和 S≤0.045%,P≤0.04%的乙炔气。3.坡口角度78°左右,间隙2.5～3毫米,不留钝边。4.管子的焊接间隙,用夹具自然对准 According to our factory practice over the past few years proved that 10 chrome silicon molybdenum vanadium 7 pipe (φ42 × 3.5 mm) is not easy to grasp the manual gas welding. We follow the teachings of Chairman Mao, the great leader, on “We must recognize difficulties, analyze difficulties and fight difficulties.” We should take seriously the difficulties in practical work so that we may initially grasp the gas welding process of such pipes. Here is a brief introduction: Preparation before welding 1. Before welding wire and bevel rust, oil and other dirt to be cleaned. 2. Use qualified welding wire, such as welding 08 Cr molybdenum vanadium or welding 12 molybdenum chrome wire, diameter 3 mm and S ≤ 0.045%, P ≤ 0.04% of acetylene gas. 3. Bevel angle of about 78 °, the gap of 2.5 to 3 mm, leaving no blunt edge. 4. Pipe welding gap, with the natural alignment of the fixture