Manufacturing essentials of butt welding elbow

1. The welding rod for butt welding elbow shall be kept dry during use. The titanium calcium type shall be dried at 150 ℃ for 1 hour, and the low hydrogen type shall be dried at 200-250 ℃ for 1 hour (repeated drying is not allowed, otherwise the coating is easy to crack and peel off), so as to prevent oil and other dirt from increasing the carbon content of the weld and affecting the quality of the weldment. During elbow welding, carbides are precipitated by repeated heating, which reduces the actual report and mechanical properties. The post welding hardenability is large and cracks are easy to occur. If the same type of electrode is used for welding, preheating above 300 ℃ and slow cooling at about 700 ℃ after welding are required. If the weldment cannot be subject to post weld heat treatment, chromium nickel stainless steel electrode shall be selected

2. In order to improve the corrosion resistance and weldability of stainless steel elbow based on the actual effect, an appropriate amount of stable elements Ti, Nb, Mo, etc. shall be added. The weldability is better. When the same type of chromium stainless steel electrode is used, it shall be preheated above 200 ℃ and tempered at about 800 ℃ after welding. If the weldment cannot be heat treated, chromium nickel stainless steel electrode shall be selected