Main points of producting 1.5D stainless steel pipe elbow

Main points of producting 1.5D stainless steel pipe elbow

Since most of these ss pipe fittings are used for welding, in order to improve the welding quality, the ends are beveled, leaving a certain angle and a certain edge. This requirement is also relatively strict, how thick the edge is, what the angle is, and the deviation range. There are regulations, and there are many more geometric dimensions than pipe fittings.

The surface quality and mechanical properties of the elbow are basically the same as those of the pipe. In order to facilitate welding, the steel material of the pipe to be connected must be the same.

Production points:

1. The welding rod should be kept dry when used. The titanium-calcium type should be dried at 150°C for 1 hour, and the low-hydrogen type should be dried at 200-250°C for 1 hour (drying cannot be repeated multiple times, otherwise the coating will easily crack and peel off) to prevent the welding rod from cracking. The coating will stick to oil and other dirt, so as not to increase the carbon content of the weld and affect the quality of the weldment.

During elbow welding, carbides will precipitate due to repeated heating, reducing corrosion resistance and mechanical properties. It is highly hardenable after welding and prone to cracks.

If the same type of electrode is used for welding, preheating above 300°C and slow cooling at about 700°C after welding must be carried out. If the weldment cannot be subjected to post-weld heat treatment, chromium-nickel stainless steel electrodes should be used.

2. In order to improve the corrosion resistance and weldability of stainless steel elbows, appropriate amounts of stabilizing elements Ti, Nb, Mo, etc. are added to improve the weldability.

When using the same type of chromium stainless steel electrode, preheating above 200℃ and tempering treatment at about 800℃ after welding should be carried out. If the weldment cannot be heat treated, chromium-nickel stainless steel welding rods should be used.