首先要看nd鋼管的表麵（miàn）。觀察亮度和表（biǎo）麵有無漏焊和脫皮等表麵（miàn）問題。好的nd鋼管表麵色澤光（guāng）亮，一般（bān）情況下不會生鏽。 第（dì）二點就是看材質。化學（xué）成分是nd鋼管的基礎。檢查化學成分是（shì）否（fǒu）達標是nd鋼管很重要的檢查（chá）方式。還有就是檢查是否精煉爐的材料。 第三（sān）點就是要看做工。圓管的圓度、方管（guǎn）的方度、表麵的處理、nd鋼管兩端的處理、還有很重（chóng）要（yào）的一點就是整隻鋼管的平直度。
First of all, we should look at the surface of ND steel pipe. Observe the brightness and surface problems such as welding leakage and peeling. A good ND steel pipe has a bright surface and will not rust in general. The second point is to look at the material. Chemical composition is the basis of ND steel pipe. Checking whether the chemical composition is up to the standard is an important inspection method for ND steel pipes. The other is to check whether the material of the refining furnace is available. The third point is to look at the workmanship. Roundness of circular pipe, squareness of square pipe, surface treatment, treatment of both ends of ND steel pipe, and a very important point is the flatness of the whole steel pipe.
最後，好的nd鋼管（guǎn）廠家擁有好的管理層、好的操作工、好的製度、有一定（dìng）的（de）知名度和信（xìn）譽度（dù），產出來的產品自然也能滿足客戶的高端要求。而一些（xiē）小的或者不正規的鋼管廠家生產出來nd鋼管不僅在外觀上與好的nd鋼管有（yǒu）差距（jù），其堅硬程度、韌性，也有很大的（de）差距。
Finally, a good ND steel pipe manufacturer has good management, good operators, good system, a certain degree of popularity and credibility, and the products produced can naturally meet the high-end requirements of customers. And some small or irregular steel pipe manufacturers produced ND steel pipe not only in appearance and good ND steel pipe has a gap, its hardness, toughness, but also a big gap.
nd鋼管良（liáng）好的溫度控製試管冶金過程的順利完（wán）成，如氧化脫磷的保證不僅要求高，高堿度渣，還需要具有良好的耐高溫配合。這是強調理性的早期脫磷。因（yīn）為這（zhè）時溫度低（dī）有利於關盤;在氧化（huà）精（jīng）煉期間，造成活性炭氧沸騰，要求（qiú）具有（yǒu）高溫（大於1550?）;冶金工程使爐侯處理和周圍澆鑄正常為（wéi），根（gēn）據使用的不（bú）同的過程中，要（yào）求爐早鋼液具有過熱度的必須的，以補償出鋼過程中，與爐輸送，處（chù）理（lǐ）的精煉和鋼液外溫（wēn）度的損失。
The smooth completion of the metallurgical process of ND steel tube with good temperature control, such as the guarantee of oxidative dephosphorization, requires not only high requirements, high basicity slag, but also good high temperature resistance cooperation. This is to emphasize rational early dephosphorization. Because the low temperature is beneficial to shut down at this time; during the oxidation refining period, the activated carbon oxygen boiling is caused, requiring a high temperature (greater than 1550); metallurgical engineering makes the furnace processing and surrounding casting normal; according to the different process used, it is necessary to require the furnace early molten steel to have superheat, in order to compensate for the loss of refining and molten steel temperature in the process of tapping, conveying with the furnace, processing.
