1·They are made of carbon chromium steel and are hardened and ground.
这些内圈是碳铬钢制造的，并经过淬硬和研磨。
2·But because the nickel is a scarce resource, it should try to use other alloying elements substitution of nickel chromium steel.
但由于镍是较稀缺的资源，故应尽量采用其他合金元素代用镍铬钢。
3·Model 410 - martensite (high-strength chromium steel), good wear resistance, corrosion resistance is poor.
型号410——马氏体（高强度铬钢），耐磨性好，抗腐蚀性较差。