首先要看nd鋼管的（de）表麵。觀察亮度和表麵有無漏焊和脫皮等（děng）表麵問題。好的nd鋼管表麵色澤光亮，一般情況下不會（huì）生鏽。 第二點就是看材（cái）質。化學成分是（shì）nd鋼管的基礎。檢查化學成分是否達標（biāo）是nd鋼（gāng）管很重（chóng）要的檢查方式。還有就是檢查是否精煉（liàn）爐的材料。 第三點就是要看做工。圓管的圓度（dù）、方管的方度、表麵的處理、nd鋼管兩（liǎng）端的處理、還有（yǒu）很重要的一點就（jiù）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鋼管廠家擁有好的（de）管理層、好的操作工、好（hǎo）的製度、有一（yī）定（dìng）的知名度和信譽度，產出來（lái）的產品自然也能滿足客戶的高端（duān）要求（qiú）。而一些小的或者不正（zhèng）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，其堅硬程度、韌性，也有很大的差（chà）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鋼管良好的溫（wēn）度控製試（shì）管冶金過程的順利完成，如氧化脫磷的保證不僅要求（qiú）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（de）早（zǎo）期脫磷。因為這（zhè）時溫度低有（yǒu）利於關盤;在氧化精（jīng）煉期間，造成活性（xìng）炭氧沸騰，要求具有（yǒu）高溫（大於1550?）;冶金工程使爐侯處理和周圍澆鑄正常為，根據使（shǐ）用（yòng）的不同的過程中，要求（qiú）爐（lú）早鋼液具有過熱度（dù）的必須的，以補償出鋼過程中，與（yǔ）爐輸送，處理的精煉和鋼液外溫度的（de）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.
