Qingdao Yingli Machinery Co., Ltd.
Company Address: High-Tech Industrial Park, Laoshan,Qingdao,China
E-mail: info@yinglimachinery.com
Zip/Postal Code: 266000
Tel Number: 86-532-88910996
Fax Number: 86-532-88910969
If the inner and outer surfaces of 304 stainless steel tubes are black, there are three ways to avoid this:
1. Improve the purity of argon used for welding 304 stainless steel tube into pure argon.
2. Argon gas should be used to protect the back.
3. Use a backside protector on the back, which is a protector that can save argon gas.