首先要看nd鋼管的表麵。觀察亮度和（hé）表麵有無漏焊和脫皮等表麵問題。好的nd鋼管表麵色澤光亮，一般情況下不會生鏽。 第二點就是看材質。化學成分是nd鋼管的基礎。檢查化學成（chéng）分是否達標是nd鋼管很重要（yào）的檢查方式。還有就是檢查是否精煉（liàn）爐的材料。 第三點就是要看做（zuò）工。圓管的圓度、方管的方度、表麵的處理、nd鋼管兩端的處理、還有很重要的一點就（jiù）是整隻鋼管的平直度（dù）。
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鋼管廠家擁有好的管理層、好（hǎo）的操作工、好的製度、有（yǒu）一定的知名度和信（xìn）譽度，產出來的產品自然也能（néng）滿足客戶的高端要求。而一些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鋼管有差距，其堅硬程度、韌性，也有很大的差（chà）距（jù）。
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（gāng）管（guǎn）良好的溫（wēn）度（dù）控製試管冶金過程（chéng）的順（shùn）利完成，如氧化脫磷的保證不僅要求高，高堿度渣（zhā），還需（xū）要具有良好的耐高溫配合。這是強調（diào）理性的早期脫磷。因為這時（shí）溫度低有利於關盤;在氧化（huà）精煉期間，造成（chéng）活性炭氧沸騰，要求（qiú）具（jù）有高溫（wēn）（大於1550?）;冶金工程使爐侯處理（lǐ）和周圍澆鑄正常為（wéi），根據使用的不同的過程中，要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（shū）送，處理的精（jīng）煉和鋼（gāng）液外溫度的損失。
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.
